Web interface timed out accessed from public network behind NAT

Hello everyone, here is the simplified network diagram:

[Internet]==[Firewall]==[Switch]==[Graylog]

The firewall is doing 1-to-1 SNAT to the graylog. I can easily access the server from the private subnet. From Internet, however, it timed out (see the following screenshot:)

The graylog config file beginning at HTTP settings:


###############
# HTTP settings
###############

#### HTTP bind address
#
# The network interface used by the Graylog HTTP interface.
#
# This network interface must be accessible by all Graylog nodes in the cluster and by all clients
# using the Graylog web interface.
#
# If the port is omitted, Graylog will use port 9000 by default.
#
# Default: 127.0.0.1:9000
#http_bind_address = 127.0.0.1:9000
#http_bind_address = [2001:db8::1]:9000
http_bind_address = 192.168.169.100:9000
#### HTTP publish URI
#
# The HTTP URI of this Graylog node which is used to communicate with the other Graylog nodes in the cluster and by all
# clients using the Graylog web interface.
#
# The URI will be published in the cluster discovery APIs, so that other Graylog nodes will be able to find and connect to this Graylog node.
#
# This configuration setting has to be used if this Graylog node is available on another network interface than $http_bind_address,
# for example if the machine has multiple network interfaces or is behind a NAT gateway.
#
# If $http_bind_address contains a wildcard IPv4 address (0.0.0.0), the first non-loopback IPv4 address of this machine will be used.
# This configuration setting *must not* contain a wildcard address!
#
# Default: http://$http_bind_address/
#http_publish_uri = http://192.168.1.1:9000/

#### External Graylog URI
#
# The public URI of Graylog which will be used by the Graylog web interface to communicate with the Graylog REST API.
#
# The external Graylog URI usually has to be specified, if Graylog is running behind a reverse proxy or load-balancer
# and it will be used to generate URLs addressing entities in the Graylog REST API (see $http_bind_address).
#
# When using Graylog Collector, this URI will be used to receive heartbeat messages and must be accessible for all collectors.
#
# This setting can be overriden on a per-request basis with the "X-Graylog-Server-URL" HTTP request header.
#
# Default: $http_publish_uri
#http_external_uri =

#### Enable CORS headers for HTTP interface
#
# This is necessary for JS-clients accessing the server directly.
# If these are disabled, modern browsers will not be able to retrieve resources from the server.
# This is enabled by default. Uncomment the next line to disable it.
#http_enable_cors = false

#### Enable GZIP support for HTTP interface
#
# This compresses API responses and therefore helps to reduce
# overall round trip times. This is enabled by default. Uncomment the next line to disable it.
#http_enable_gzip = false

# The maximum size of the HTTP request headers in bytes.
#http_max_header_size = 8192

# The size of the thread pool used exclusively for serving the HTTP interface.
#http_thread_pool_size = 16

################
# HTTPS settings
################

#### Enable HTTPS support for the HTTP interface
#
# This secures the communication with the HTTP interface with TLS to prevent request forgery and eavesdropping.
#
# Default: false
#http_enable_tls = true

# The X.509 certificate chain file in PEM format to use for securing the HTTP interface.
#http_tls_cert_file = /path/to/graylog.crt

# The PKCS#8 private key file in PEM format to use for securing the HTTP interface.
#http_tls_key_file = /path/to/graylog.key

# The password to unlock the private key used for securing the HTTP interface.
#http_tls_key_password = secret


# Comma separated list of trusted proxies that are allowed to set the client address with X-Forwarded-For
# header. May be subnets, or hosts.
#trusted_proxies = 127.0.0.1/32, 0:0:0:0:0:0:0:1/128

# List of Elasticsearch hosts Graylog should connect to.
# Need to be specified as a comma-separated list of valid URIs for the http ports of your elasticsearch nodes.
# If one or more of your elasticsearch hosts require authentication, include the credentials in each node URI that
# requires authentication.
#
# Default: http://127.0.0.1:9200
#elasticsearch_hosts = http://node1:9200,http://user:password@node2:19200

# Maximum amount of time to wait for successfull connection to Elasticsearch HTTP port.
#
# Default: 10 Seconds
#elasticsearch_connect_timeout = 10s

# Maximum amount of time to wait for reading back a response from an Elasticsearch server.
#
# Default: 60 seconds
#elasticsearch_socket_timeout = 60s

# Maximum idle time for an Elasticsearch connection. If this is exceeded, this connection will
# be tore down.
#
# Default: inf
#elasticsearch_idle_timeout = -1s

# Maximum number of total connections to Elasticsearch.
#
# Default: 200
#elasticsearch_max_total_connections = 200

# Maximum number of total connections per Elasticsearch route (normally this means per
# elasticsearch server).
#
# Default: 20
#elasticsearch_max_total_connections_per_route = 20

# Maximum number of times Graylog will retry failed requests to Elasticsearch.
#
# Default: 2
#elasticsearch_max_retries = 2

# Enable automatic Elasticsearch node discovery through Nodes Info,
# see https://www.elastic.co/guide/en/elasticsearch/reference/5.4/cluster-nodes-info.html
#
# WARNING: Automatic node discovery does not work if Elasticsearch requires authentication, e. g. with Shield.
#
# Default: false
#elasticsearch_discovery_enabled = true

# Filter for including/excluding Elasticsearch nodes in discovery according to their custom attributes,
# see https://www.elastic.co/guide/en/elasticsearch/reference/5.4/cluster.html#cluster-nodes
#
# Default: empty
#elasticsearch_discovery_filter = rack:42

# Frequency of the Elasticsearch node discovery.
#
# Default: 30s
# elasticsearch_discovery_frequency = 30s

# Set the default scheme when connecting to Elasticsearch discovered nodes
#
# Default: http (available options: http, https)
#elasticsearch_discovery_default_scheme = http

# Enable payload compression for Elasticsearch requests.
#
# Default: false
#elasticsearch_compression_enabled = true

# Enable use of "Expect: 100-continue" Header for Elasticsearch index requests.
# If this is disabled, Graylog cannot properly handle HTTP 413 Request Entity Too Large errors.
#
# Default: true
#elasticsearch_use_expect_continue = true

# Graylog will use multiple indices to store documents in. You can configured the strategy it uses to determine
# when to rotate the currently active write index.
# It supports multiple rotation strategies:
#   - "count" of messages per index, use elasticsearch_max_docs_per_index below to configure
#   - "size" per index, use elasticsearch_max_size_per_index below to configure
# valid values are "count", "size" and "time", default is "count"
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
rotation_strategy = count

# (Approximate) maximum number of documents in an Elasticsearch index before a new index
# is being created, also see no_retention and elasticsearch_max_number_of_indices.
# Configure this if you used 'rotation_strategy = count' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_max_docs_per_index = 20000000

# (Approximate) maximum size in bytes per Elasticsearch index on disk before a new index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1GB.
# Configure this if you used 'rotation_strategy = size' above.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_max_size_per_index = 1073741824

# (Approximate) maximum time before a new Elasticsearch index is being created, also see
# no_retention and elasticsearch_max_number_of_indices. Default is 1 day.
# Configure this if you used 'rotation_strategy = time' above.
# Please note that this rotation period does not look at the time specified in the received messages, but is
# using the real clock value to decide when to rotate the index!
# Specify the time using a duration and a suffix indicating which unit you want:
#  1w  = 1 week
#  1d  = 1 day
#  12h = 12 hours
# Permitted suffixes are: d for day, h for hour, m for minute, s for second.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_max_time_per_index = 1d

# Disable checking the version of Elasticsearch for being compatible with this Graylog release.
# WARNING: Using Graylog with unsupported and untested versions of Elasticsearch may lead to data loss!
#elasticsearch_disable_version_check = true

# Disable message retention on this node, i. e. disable Elasticsearch index rotation.
#no_retention = false

# How many indices do you want to keep?
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_max_number_of_indices = 20

# Decide what happens with the oldest indices when the maximum number of indices is reached.
# The following strategies are availble:
#   - delete # Deletes the index completely (Default)
#   - close # Closes the index and hides it from the system. Can be re-opened later.
#
# ATTENTION: These settings have been moved to the database in 2.0. When you upgrade, make sure to set these
#            to your previous 1.x settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
retention_strategy = delete

# How many Elasticsearch shards and replicas should be used per index? Note that this only applies to newly created indices.
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_shards = 4
elasticsearch_replicas = 0

# Prefix for all Elasticsearch indices and index aliases managed by Graylog.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_index_prefix = graylog

# Name of the Elasticsearch index template used by Graylog to apply the mandatory index mapping.
# Default: graylog-internal
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#elasticsearch_template_name = graylog-internal

# Do you want to allow searches with leading wildcards? This can be extremely resource hungry and should only
# be enabled with care. See also: http://docs.graylog.org/en/2.1/pages/queries.html
allow_leading_wildcard_searches = false

# Do you want to allow searches to be highlighted? Depending on the size of your messages this can be memory hungry and
# should only be enabled after making sure your Elasticsearch cluster has enough memory.
allow_highlighting = false

# Analyzer (tokenizer) to use for message and full_message field. The "standard" filter usually is a good idea.
# All supported analyzers are: standard, simple, whitespace, stop, keyword, pattern, language, snowball, custom
# Elasticsearch documentation: https://www.elastic.co/guide/en/elasticsearch/reference/2.3/analysis.html
# Note that this setting only takes effect on newly created indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
elasticsearch_analyzer = standard

# Global request timeout for Elasticsearch requests (e. g. during search, index creation, or index time-range
# calculations) based on a best-effort to restrict the runtime of Elasticsearch operations.
# Default: 1m
#elasticsearch_request_timeout = 1m

# Global timeout for index optimization (force merge) requests.
# Default: 1h
#elasticsearch_index_optimization_timeout = 1h

# Maximum number of concurrently running index optimization (force merge) jobs.
# If you are using lots of different index sets, you might want to increase that number.
# Default: 20
#elasticsearch_index_optimization_jobs = 20

# Time interval for index range information cleanups. This setting defines how often stale index range information
# is being purged from the database.
# Default: 1h
#index_ranges_cleanup_interval = 1h

# Time interval for the job that runs index field type maintenance tasks like cleaning up stale entries. This doesn't
# need to run very often.
# Default: 1h
#index_field_type_periodical_interval = 1h

# Batch size for the Elasticsearch output. This is the maximum (!) number of messages the Elasticsearch output
# module will get at once and write to Elasticsearch in a batch call. If the configured batch size has not been
# reached within output_flush_interval seconds, everything that is available will be flushed at once. Remember
# that every outputbuffer processor manages its own batch and performs its own batch write calls.
# ("outputbuffer_processors" variable)
output_batch_size = 500

# Flush interval (in seconds) for the Elasticsearch output. This is the maximum amount of time between two
# batches of messages written to Elasticsearch. It is only effective at all if your minimum number of messages
# for this time period is less than output_batch_size * outputbuffer_processors.
output_flush_interval = 1

# As stream outputs are loaded only on demand, an output which is failing to initialize will be tried over and
# over again. To prevent this, the following configuration options define after how many faults an output will
# not be tried again for an also configurable amount of seconds.
output_fault_count_threshold = 5
output_fault_penalty_seconds = 30

# The number of parallel running processors.
# Raise this number if your buffers are filling up.
processbuffer_processors = 5
outputbuffer_processors = 3

# The following settings (outputbuffer_processor_*) configure the thread pools backing each output buffer processor.
# See https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ThreadPoolExecutor.html for technical details

# When the number of threads is greater than the core (see outputbuffer_processor_threads_core_pool_size),
# this is the maximum time in milliseconds that excess idle threads will wait for new tasks before terminating.
# Default: 5000
#outputbuffer_processor_keep_alive_time = 5000

# The number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
# Default: 3
#outputbuffer_processor_threads_core_pool_size = 3

# The maximum number of threads to allow in the pool
# Default: 30
#outputbuffer_processor_threads_max_pool_size = 30

# UDP receive buffer size for all message inputs (e. g. SyslogUDPInput).
#udp_recvbuffer_sizes = 1048576

# Wait strategy describing how buffer processors wait on a cursor sequence. (default: sleeping)
# Possible types:
#  - yielding
#     Compromise between performance and CPU usage.
#  - sleeping
#     Compromise between performance and CPU usage. Latency spikes can occur after quiet periods.
#  - blocking
#     High throughput, low latency, higher CPU usage.
#  - busy_spinning
#     Avoids syscalls which could introduce latency jitter. Best when threads can be bound to specific CPU cores.
processor_wait_strategy = blocking

# Size of internal ring buffers. Raise this if raising outputbuffer_processors does not help anymore.
# For optimum performance your LogMessage objects in the ring buffer should fit in your CPU L3 cache.
# Must be a power of 2. (512, 1024, 2048, ...)
ring_size = 65536

inputbuffer_ring_size = 65536
inputbuffer_processors = 2
inputbuffer_wait_strategy = blocking

# Enable the disk based message journal.
message_journal_enabled = true

# The directory which will be used to store the message journal. The directory must be exclusively used by Graylog and
# must not contain any other files than the ones created by Graylog itself.
#
# ATTENTION:
#   If you create a seperate partition for the journal files and use a file system creating directories like 'lost+found'
#   in the root directory, you need to create a sub directory for your journal.
#   Otherwise Graylog will log an error message that the journal is corrupt and Graylog will not start.
message_journal_dir = /var/lib/graylog-server/journal

# Journal hold messages before they could be written to Elasticsearch.
# For a maximum of 12 hours or 5 GB whichever happens first.
# During normal operation the journal will be smaller.
#message_journal_max_age = 12h
#message_journal_max_size = 5gb

#message_journal_flush_age = 1m
#message_journal_flush_interval = 1000000
#message_journal_segment_age = 1h
#message_journal_segment_size = 100mb

# Number of threads used exclusively for dispatching internal events. Default is 2.
#async_eventbus_processors = 2

# How many seconds to wait between marking node as DEAD for possible load balancers and starting the actual
# shutdown process. Set to 0 if you have no status checking load balancers in front.
lb_recognition_period_seconds = 3

# Journal usage percentage that triggers requesting throttling for this server node from load balancers. The feature is
# disabled if not set.
#lb_throttle_threshold_percentage = 95

# Every message is matched against the configured streams and it can happen that a stream contains rules which
# take an unusual amount of time to run, for example if its using regular expressions that perform excessive backtracking.
# This will impact the processing of the entire server. To keep such misbehaving stream rules from impacting other
# streams, Graylog limits the execution time for each stream.
# The default values are noted below, the timeout is in milliseconds.
# If the stream matching for one stream took longer than the timeout value, and this happened more than "max_faults" times
# that stream is disabled and a notification is shown in the web interface.
#stream_processing_timeout = 2000
#stream_processing_max_faults = 3

# Since 0.21 the Graylog server supports pluggable output modules. This means a single message can be written to multiple
# outputs. The next setting defines the timeout for a single output module, including the default output module where all
# messages end up.
#
# Time in milliseconds to wait for all message outputs to finish writing a single message.
#output_module_timeout = 10000

# Time in milliseconds after which a detected stale master node is being rechecked on startup.
#stale_master_timeout = 2000

# Time in milliseconds which Graylog is waiting for all threads to stop on shutdown.
#shutdown_timeout = 30000

# MongoDB connection string
# See https://docs.mongodb.com/manual/reference/connection-string/ for details
mongodb_uri = mongodb://localhost/graylog

# Authenticate against the MongoDB server
# '+'-signs in the username or password need to be replaced by '%2B'
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017/graylog

# Use a replica set instead of a single host
#mongodb_uri = mongodb://grayloguser:secret@localhost:27017,localhost:27018,localhost:27019/graylog?replicaSet=rs01

# DNS Seedlist https://docs.mongodb.com/manual/reference/connection-string/#dns-seedlist-connection-format
#mongodb_uri = mongodb+srv://server.example.org/graylog

# Increase this value according to the maximum connections your MongoDB server can handle from a single client
# if you encounter MongoDB connection problems.
mongodb_max_connections = 1000

# Number of threads allowed to be blocked by MongoDB connections multiplier. Default: 5
# If mongodb_max_connections is 100, and mongodb_threads_allowed_to_block_multiplier is 5,
# then 500 threads can block. More than that and an exception will be thrown.
# http://api.mongodb.com/java/current/com/mongodb/MongoOptions.html#threadsAllowedToBlockForConnectionMultiplier
mongodb_threads_allowed_to_block_multiplier = 5


# Email transport
#transport_email_enabled = false
#transport_email_hostname = mail.example.com
#transport_email_port = 587
#transport_email_use_auth = true
#transport_email_auth_username = you@example.com
#transport_email_auth_password = secret
#transport_email_subject_prefix = [graylog]
#transport_email_from_email = graylog@example.com

# Encryption settings
#
# ATTENTION:
#    Using SMTP with STARTTLS *and* SMTPS at the same time is *not* possible.

# Use SMTP with STARTTLS, see https://en.wikipedia.org/wiki/Opportunistic_TLS
#transport_email_use_tls = true

# Use SMTP over SSL (SMTPS), see https://en.wikipedia.org/wiki/SMTPS
# This is deprecated on most SMTP services!
#transport_email_use_ssl = false


# Specify and uncomment this if you want to include links to the stream in your stream alert mails.
# This should define the fully qualified base url to your web interface exactly the same way as it is accessed by your users.
#transport_email_web_interface_url = https://graylog.example.com

# The default connect timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 5s
#http_connect_timeout = 5s

# The default read timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_read_timeout = 10s

# The default write timeout for outgoing HTTP connections.
# Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
# Default: 10s
#http_write_timeout = 10s

# HTTP proxy for outgoing HTTP connections
# ATTENTION: If you configure a proxy, make sure to also configure the "http_non_proxy_hosts" option so internal
#            HTTP connections with other nodes does not go through the proxy.
# Examples:
#   - http://proxy.example.com:8123
#   - http://username:password@proxy.example.com:8123
#http_proxy_uri =

# A list of hosts that should be reached directly, bypassing the configured proxy server.
# This is a list of patterns separated by ",". The patterns may start or end with a "*" for wildcards.
# Any host matching one of these patterns will be reached through a direct connection instead of through a proxy.
# Examples:
#   - localhost,127.0.0.1
#   - 10.0.*,*.example.com
#http_non_proxy_hosts =

# Disable the optimization of Elasticsearch indices after index cycling. This may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is to optimize
# cycled indices.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#disable_index_optimization = true

# Optimize the index down to <= index_optimization_max_num_segments. A higher number may take some load from Elasticsearch
# on heavily used systems with large indices, but it will decrease search performance. The default is 1.
#
# ATTENTION: These settings have been moved to the database in Graylog 2.2.0. When you upgrade, make sure to set these
#            to your previous settings so they will be migrated to the database!
#            This configuration setting is only used on the first start of Graylog. After that,
#            index related settings can be changed in the Graylog web interface on the 'System / Indices' page.
#            Also see http://docs.graylog.org/en/2.3/pages/configuration/index_model.html#index-set-configuration.
#index_optimization_max_num_segments = 1

# The threshold of the garbage collection runs. If GC runs take longer than this threshold, a system notification
# will be generated to warn the administrator about possible problems with the system. Default is 1 second.
#gc_warning_threshold = 1s

# Connection timeout for a configured LDAP server (e. g. ActiveDirectory) in milliseconds.
#ldap_connection_timeout = 2000

# Disable the use of SIGAR for collecting system stats
#disable_sigar = false

# The default cache time for dashboard widgets. (Default: 10 seconds, minimum: 1 second)
#dashboard_widget_default_cache_time = 10s

# For some cluster-related REST requests, the node must query all other nodes in the cluster. This is the maximum number
# of threads available for this. Increase it, if '/cluster/*' requests take long to complete.
# Should be http_thread_pool_size * average_cluster_size if you have a high number of concurrent users.
proxied_requests_thread_pool_size = 32

# The server is writing processing status information to the database on a regular basis. This setting controls how
# often the data is written to the database.
# Default: 1s (cannot be less than 1s)
#processing_status_persist_interval = 1s

# Configures the threshold for detecting outdated processing status records. Any records that haven't been updated
# in the configured threshold will be ignored.
# Default: 1m (one minute)
#processing_status_update_threshold = 1m

# Configures the journal write rate threshold for selecting processing status records. Any records that have a lower
# one minute rate than the configured value might be ignored. (dependent on number of messages in the journal)
# Default: 1
#processing_status_journal_write_rate_threshold = 1

# Configures the prefix used for graylog event indices
# Default: gl-events
#default_events_index_prefix = gl-events

# Configures the prefix used for graylog system event indices
# Default: gl-system-events
#default_system_events_index_prefix = gl-system-events

# Automatically load content packs in "content_packs_dir" on the first start of Graylog.
#content_packs_loader_enabled = false

# The directory which contains content packs which should be loaded on the first start of Graylog.
#content_packs_dir = data/contentpacks

# A comma-separated list of content packs (files in "content_packs_dir") which should be applied on
# the first start of Graylog.
# Default: empty
#content_packs_auto_install = grok-patterns.json

# The allowed TLS protocols for system wide TLS enabled servers. (e.g. message inputs, http interface)
# Setting this to an empty value, leaves it up to system libraries and the used JDK to chose a default.
# Default: TLSv1.2,TLSv1.3
#enabled_tls_protocols= TLSv1.2,TLSv1.3

The log:

2020-02-15T17:09:49.579+08:00 INFO  [NetworkListener] Started listener bound to [192.168.169.100:9000]
2020-02-15T17:09:49.581+08:00 INFO  [HttpServer] [HttpServer] Started.
2020-02-15T17:09:49.581+08:00 INFO  [JerseyService] Started REST API at <192.168.169.100:9000>
2020-02-15T17:09:49.581+08:00 INFO  [ServiceManagerListener] Services are healthy
2020-02-15T17:09:49.583+08:00 INFO  [ServerBootstrap] Services started, startup times in ms: {InputSetupService [RUNNING]=2, JobSchedulerService [RUNNING]=38, OutputSetupService [RUNNING]=38, JournalReader [RUNNING]=39, EtagService [RUNNING]=39, BufferSynchronizerService [RUNNING]=39, UrlWhitelistService [RUNNING]=50, MongoDBProcessingStatusRecorderService [RUNNING]=52, GracefulShutdownService [RUNNING]=55, ConfigurationEtagService [RUNNING]=95, KafkaJournal [RUNNING]=112, StreamCacheService [RUNNING]=128, LookupTableService [RUNNING]=163, PeriodicalsService [RUNNING]=221, JerseyService [RUNNING]=28614}
2020-02-15T17:09:49.584+08:00 INFO  [InputSetupService] Triggering launching persisted inputs, node transitioned from Uninitialized [LB:DEAD] to Running [LB:ALIVE]
2020-02-15T17:09:49.584+08:00 INFO  [ServerBootstrap] Graylog server up and running.
2020-02-15T17:09:49.585+08:00 ERROR [AuditLogger] Unable to write audit log entry because there is no valid license.

Thanks in advance for any help.

SNAT is needed for packets from Graylog to Internet.
For packets from Internet to Graylog you need to configure DNAT or port forwarding, so firewall_public_ip:firewall_public_port will be mapped to 192.168.169.100:9000

1 Like

thanks zoulja for the suggestion,

I also tried the DstNAT way and the outcome is the same. The browser keeps loading the webpage and eventually times out.

I even changed the firewall from a different vendor but it did not work.

But thanks for your response.

You don’t need to guess and try to change vendors, you just need to understand network flow clearly, including routing(L3) and ports usage(L4).

Of course it requires a little bit practice, have a pen and a paper and draw a packet’s path, both incoming and outgoing, asking yourself what’s the route and policy is used on each hop to proceed this packet

I can assist if you still have some questions

Thanks. I think the policy on the firewall is alright. So I think there must be something wrong with the graylog config but I can’t figure it out.

the problem is - that http_external_uri need to be the URL where your browser can reach Graylog.

I guess you can’t reach http://192.168.1.1:9000/ when you are not locally connected.

thanks jan,

does that mean the server must attach to a NIC with public IP address and add the http_external_url = <Public_IP> to the config file?

I want to keep the Graylog server behind the firewall and I don’t want to use proxy.

Simple NAT setup really impossible?

he @bbfunde

no that is not impossible - but you needed to have the header x-graylog-server-uri ingested that your Browser knows where to connect to Graylog.

Cause Graylog is actually a browser application that connects to a backend API - what is the Graylog server - it always needs to know how to access the backend.

Thanks @jan for the help.

Sorry I am not familiar with Linux, could you help tell me how to set the http header in Graylog server or point me to a reference?

Do I need to install and use Nginx or Apache on the server?

Thanks again.

he @bbfunde

you need to set http_external_uri in the graylog server.conf

https://docs.graylog.org/en/3.2/pages/configuration/server.conf.html#web-rest-api

OR

you need to install nginx/apache/haproxy (or any other proxy system you like to use) that can add the http header into the stream from Graylog to your Browser.

In clear words, you need either on the system where you enter the network (the NAT host) a browser or on you local machine.

OR

you use some kind of browser add-on that enables you to ingest the header.

yes, I can access it now after using the modify header add-on and add the X-Graylog-Server-URL http://<public_IP>:9000 header.

Much thanks to @jan for all the advice you have been giving.