I've configured an open connect vpn server on my vps (ubuntu 22.04) with following parameters on /etc/ocserv/ocserv.conf:
# User authentication method. Could be set multiple times and in
# that case all should succeed. To enable multiple methods use
# multiple auth directives. Available options: certificate,
# plain, pam, radius, gssapi.
#auth = "pam"
#auth = "pam[gid-min=1000]"
auth = "plain[passwd=/etc/ocserv/ocpasswd]"
#auth = "plain[passwd=./sample.passwd,otp=./sample.otp]"
#auth = "plain[passwd=./sample.passwd]"
#auth = "certificate"
#auth = "radius[config=/etc/radiusclient/radiusclient.conf,groupconfig=true]"
# Specify alternative authentication methods that are sufficient
# for authentication. That is, if set, any of the methods enabled
# will be sufficient to login.
#enable-auth = "certificate"
#enable-auth = "gssapi"
#enable-auth = "gssapi[keytab=/etc/key.tab,require-local-user-map=true,tgt-freshness-time=900]"
# Accounting methods available:
# radius: can be combined with any authentication method, it provides
# radius accounting to available users (see also stats-report-time).
#
# pam: can be combined with any authentication method, it provides
# a validation of the connecting user's name using PAM. It is
# superfluous to use this method when authentication is already
# PAM.
#
# Only one accounting method can be specified.
#acct = "radius[config=/etc/radiusclient/radiusclient.conf]"
# Use listen-host to limit to specific IPs or to the IPs of a provided
# hostname.
#listen-host = [IP|HOSTNAME]
# Use udp-listen-host to limit udp to specific IPs or to the IPs of a provided
# hostname. if not set, listen-host will be used
#udp-listen-host = [IP|HOSTNAME]
# When the server has a dynamic DNS address (that may change),
# should set that to true to ask the client to resolve again on
# reconnects.
#listen-host-is-dyndns = true
# TCP and UDP port number
# Note: These options are controlled by ocserv.socket if socket-activated
# version of systemd configuration is used
tcp-port = 443
#udp-port = 443
# Accept connections using a socket file. It accepts HTTP
# connections (i.e., without SSL/TLS unlike its TCP counterpart),
# and uses it as the primary channel. That option cannot be
# combined with certificate authentication.
#listen-clear-file = /run/ocserv-conn.socket
# The user the worker processes will be run as. It should be
# unique (no other services run as this user).
run-as-user = nobody
run-as-group = daemon
# socket file used for IPC with occtl. You only need to set that,
# if you use more than a single servers.
#occtl-socket-file = /run/occtl.socket
# socket file used for server IPC (worker-main), will be appended with .PID
# It must be accessible within the chroot environment (if any), so it is best
# specified relatively to the chroot directory.
socket-file = /run/ocserv.socket
# The default server directory. Does not require any devices present.
#chroot-dir = /var/lib/ocserv
server-cert = /etc/letsencrypt/live/{domain_name}/fullchain.pem
server-key = /etc/letsencrypt/live/{domain_name}/privkey.pem
# Diffie-Hellman parameters. Only needed if for old (pre 3.6.0
# versions of GnuTLS for supporting DHE ciphersuites.
# Can be generated using:
# certtool --generate-dh-params --outfile /etc/ocserv/dh.pem
#dh-params = /etc/ocserv/dh.pem
# In case PKCS #11, TPM or encrypted keys are used the PINs should be available
# in files. The srk-pin-file is applicable to TPM keys only, and is the
# storage root key.
#pin-file = /etc/ocserv/pin.txt
#srk-pin-file = /etc/ocserv/srkpin.txt
# The password or PIN needed to unlock the key in server-key file.
# Only needed if the file is encrypted or a PKCS #11 object. This
# is an alternative method to pin-file.
#key-pin = 1234
# The SRK PIN for TPM.
# This is an alternative method to srk-pin-file.
#srk-pin = 1234
# The Certificate Authority that will be used to verify
# client certificates (public keys) if certificate authentication
# is set.
ca-cert = /etc/ssl/certs/ssl-cert-snakeoil.pem
### All configuration options below this line are reloaded on a SIGHUP.
### The options above, will remain unchanged. Note however, that the
### server-cert, server-key, dh-params and ca-cert options will be reloaded
### if the provided file changes, on server reload. That allows certificate
### rotation, but requires the server key to remain the same for seamless
### operation. If the server key changes on reload, there may be connection
### failures during the reloading time.
isolate-workers = true
# A banner to be displayed on clients
#banner = "Welcome"
# Limit the number of clients. Unset or set to zero for unlimited.
#max-clients = 1024
max-clients = 128
# Limit the number of identical clients (i.e., users connecting
# multiple times). Unset or set to zero for unlimited.
max-same-clients = 1
# When the server receives connections from a proxy, like haproxy
# which supports the proxy protocol, set this to obtain the correct
# client addresses. The proxy protocol (v2) would then be expected in
# the TCP or UNIX socket (not the UDP one).
#listen-proxy-proto = true
# Limit the number of client connections to one every X milliseconds
# (X is the provided value). Set to zero for no limit.
#rate-limit-ms = 100
# Stats report time. The number of seconds after which each
# worker process will report its usage statistics (number of
# bytes transferred etc). This is useful when accounting like
# radius is in use.
#stats-report-time = 360
# Stats reset time. The period of time statistics kept by main/sec-mod
# processes will be reset. These are the statistics shown by cmd
# 'occtl show stats'. For daily: 86400, weekly: 604800
# This is unrelated to stats-report-time.
server-stats-reset-time = 604800
# Keepalive in seconds
keepalive = 30
# Dead peer detection in seconds.
# Note that when the client is behind a NAT this value
# needs to be short enough to prevent the NAT disassociating
# his UDP session from the port number. Otherwise the client
# could have his UDP connection stalled, for several minutes.
dpd = 60
# Dead peer detection for mobile clients. That needs to
# be higher to prevent such clients being awaken too
# often by the DPD messages, and save battery.
# The mobile clients are distinguished from the header
# 'X-AnyConnect-Identifier-Platform'.
mobile-dpd = 300
# If using DTLS, and no UDP traffic is received for this
# many seconds, attempt to send future traffic over the TCP
# connection instead, in an attempt to wake up the client
# in the case that there is a NAT and the UDP translation
# was deleted. If this is unset, do not attempt to use this
# recovery mechanism.
switch-to-tcp-timeout = 25
# MTU discovery (DPD must be enabled)
try-mtu-discovery = true
#ocsp-response = /etc/ocserv/ocsp.der
# The object identifier that will be used to read the user ID in the client
# certificate. The object identifier should be part of the certificate's DN
# Useful OIDs are:
# CN = 2.5.4.3, UID = 0.9.2342.19200300.100.1.1
cert-user-oid = 0.9.2342.19200300.100.1.1
# The object identifier that will be used to read the user group in the
# client certificate. The object identifier should be part of the certificate's
# DN. If the user may belong to multiple groups, then use multiple such fields
# in the certificate's DN. Useful OIDs are:
# OU (organizational unit) = 2.5.4.11
#cert-group-oid = 2.5.4.11
# The revocation list of the certificates issued by the 'ca-cert' above.
# See the manual to generate an empty CRL initially. The CRL will be reloaded
# periodically when ocserv detects a change in the file. To force a reload use
# SIGHUP.
#crl = /etc/ocserv/crl.pem
# Uncomment this to enable compression negotiation (LZS, LZ4).
compression = true
# Set the minimum size under which a packet will not be compressed.
# That is to allow low-latency for VoIP packets. The default size
# is 256 bytes. Modify it if the clients typically use compression
# as well of VoIP with codecs that exceed the default value.
no-compress-limit = 256
# More combinations in priority strings are available, check
# http://gnutls.org/manual/html_node/Priority-Strings.html
# E.g., the string below enforces perfect forward secrecy (PFS)
# on the main channel.
tls-priorities = "NORMAL:%SERVER_PRECEDENCE:%COMPAT:-RSA:-VERS-SSL3.0:-ARCFOUR-128:-VERS-TLS1.0:-VERS-TLS1.1"
# That option requires the established DTLS channel to use the same
# cipher as the primary TLS channel. This cannot be combined with
# listen-clear-file since the ciphersuite information is not available
# in that configuration. Note also, that this option implies that
# dtls-legacy option is false; this option cannot be enforced
# in the legacy/compat protocol.
#match-tls-dtls-ciphers = true
# The time (in seconds) that a client is allowed to stay connected prior
# to authentication
auth-timeout = 240
# The time (in seconds) that a client is allowed to stay idle (no traffic)
# before being disconnected. Unset to disable.
idle-timeout = 1200
# The time (in seconds) that a mobile client is allowed to stay idle (no
# traffic) before being disconnected. Unset to disable.
mobile-idle-timeout = 1800
# The time (in seconds) that a client is not allowed to reconnect after
# a failed authentication attempt.
min-reauth-time = 300
max-ban-score = 80
# The time (in seconds) that all score kept for a client is reset.
ban-reset-time = 300
# In case you'd like to change the default points.
#ban-points-wrong-password = 10
#ban-points-connection = 1
#ban-points-kkdcp = 1
# Cookie timeout (in seconds)
# Once a client is authenticated he's provided a cookie with
# which he can reconnect. That cookie will be invalidated if not
# used within this timeout value. This cookie remains valid, during
# the user's connected time, and after user disconnection it
# remains active for this amount of time. That setting should allow a
# reasonable amount of time for roaming between different networks.
cookie-timeout = 300
# If this is enabled (not recommended) the cookies will stay
# valid even after a user manually disconnects, and until they
# expire. This may improve roaming with some broken clients.
#persistent-cookies = true
# Whether roaming is allowed, i.e., if true a cookie is
# restricted to a single IP address and cannot be re-used
# from a different IP.
deny-roaming = false
# ReKey time (in seconds)
# ocserv will ask the client to refresh keys periodically once
# this amount of seconds is elapsed. Set to zero to disable (note
# that, some clients fail if rekey is disabled).
rekey-time = 172800
# ReKey method
# Valid options: ssl, new-tunnel
# ssl: Will perform an efficient rehandshake on the channel allowing
# a seamless connection during rekey.
# new-tunnel: Will instruct the client to discard and re-establish the channel.
# Use this option only if the connecting clients have issues with the ssl
# option.
rekey-method = ssl
#connect-script = /usr/bin/myscript
#disconnect-script = /usr/bin/myscript
# UTMP
# Register the connected clients to utmp. This will allow viewing
# the connected clients using the command 'who'.
#use-utmp = true
# Whether to enable support for the occtl tool (i.e., either through D-BUS,
# or via a unix socket).
use-occtl = true
# PID file. It can be overriden in the command line.
pid-file = /run/ocserv.pid
# Set the protocol-defined priority (SO_PRIORITY) for packets to
# be sent. That is a number from 0 to 6 with 0 being the lowest
# priority. Alternatively this can be used to set the IP Type-
# Of-Service, by setting it to a hexadecimal number (e.g., 0x20).
# This can be set per user/group or globally.
#net-priority = 3
# Set the VPN worker process into a specific cgroup. This is Linux
# specific and can be set per user/group or globally.
#cgroup = "cpuset,cpu:test"
#
# Network settings
#
# The name to use for the tun device
device = vpns
# Whether the generated IPs will be predictable, i.e., IP stays the
# same for the same user when possible.
predictable-ips = true
# The default domain to be advertised
default-domain = {domain_name}
# The pool of addresses that leases will be given from. If the leases
# are given via Radius, or via the explicit-ip? per-user config option then
# these network values should contain a network with at least a single
# address that will remain under the full control of ocserv (that is
# to be able to assign the local part of the tun device address).
# Note that, you could use addresses from a subnet of your LAN network if you
# enable proxy arp in the LAN interface (see http://ocserv.gitlab.io/www/recipes-ocserv-pseudo-bridge.html);
# in that case it is recommended to set ping-leases to true.
ipv4-network = 10.10.10.0
ipv4-netmask = 255.255.255.0
# An alternative way of specifying the network:
#ipv4-network = 192.168.1.0/24
# The IPv6 subnet that leases will be given from.
ipv6-network = fda9:4efe:7e3b:03ea::/48
# Specify the size of the network to provide to clients. It is
# generally recommended to provide clients with a /64 network in
# IPv6, but any subnet may be specified. To provide clients only
# with a single IP use the prefix 128.
#ipv6-subnet-prefix = 128
ipv6-subnet-prefix = 64
# Whether to tunnel all DNS queries via the VPN. This is the default
# when a default route is set.
tunnel-all-dns = true
# The advertized DNS server. Use multiple lines for
# multiple servers.
# dns = fc00::4be0
dns = 8.8.8.8
dns = 8.8.4.4
# The NBNS server (if any)
#nbns = 192.168.1.3
# The domains over which the provided DNS should be used. Use
# multiple lines for multiple domains.
#split-dns = example.com
# Prior to leasing any IP from the pool ping it to verify that
# it is not in use by another (unrelated to this server) host.
# Only set to true, if there can be occupied addresses in the
# IP range for leases.
ping-leases = false
# Use this option to set a link MTU value to the incoming
# connections. Unset to use the default MTU of the TUN device.
# Note that the MTU is negotiated using the value set and the
# value sent by the peer.
#mtu = 1420
# Unset to enable bandwidth restrictions (in bytes/sec). The
# setting here is global, but can also be set per user or per group.
#rx-data-per-sec = 40000
#tx-data-per-sec = 40000
# The number of packets (of MTU size) that are available in
# the output buffer. The default is low to improve latency.
# Setting it higher will improve throughput.
#output-buffer = 10
# Routes to be forwarded to the client. If you need the
# client to forward routes to the server, you may use the
# config-per-user/group or even connect and disconnect scripts.
#
# To set the server as the default gateway for the client just
# comment out all routes from the server, or use the special keyword
# 'default'.
#route = 10.0.0.0/8
#route = 172.16.0.0/12
#route = 192.168.0.0/16
#route = fd00::/8
#route = default
# Subsets of the routes above that will not be routed by
# the server.
#no-route = 192.168.5.0/255.255.255.0
# Note the that following two firewalling options currently are available
# in Linux systems with iptables software.
# If set, the script /usr/bin/ocserv-fw will be called to restrict
# the user to its allowed routes and prevent him from accessing
# any other routes. In case of defaultroute, the no-routes are restricted.
# All the routes applied by ocserv can be reverted using /usr/bin/ocserv-fw
# --removeall. This option can be set globally or in the per-user configuration.
#restrict-user-to-routes = true
# This option implies restrict-user-to-routes set to true. If set, the
# script /usr/bin/ocserv-fw will be called to restrict the user to
# access specific ports in the network. This option can be set globally
# or in the per-user configuration.
#restrict-user-to-ports = "tcp(443), tcp(80), udp(443), sctp(99), tcp(583), icmp(), icmpv6()"
# You could also use negation, i.e., block the user from accessing these ports only.
#restrict-user-to-ports = "!(tcp(443), tcp(80))"
# When set to true, all client's iroutes are made visible to all
# connecting clients except for the ones offering them. This option
# only makes sense if config-per-user is set.
#expose-iroutes = true
# Groups that a client is allowed to select from.
# A client may belong in multiple groups, and in certain use-cases
# it is needed to switch between them. For these cases the client can
# select prior to authentication. Add multiple entries for multiple groups.
# The group may be followed by a user-friendly name in brackets.
#select-group = group1
#select-group = group2[My special group]
# The name of the (virtual) group that if selected it would assign the user
# to its default group.
#default-select-group = DEFAULT
# Instead of specifying manually all the allowed groups, you may instruct
# ocserv to scan all available groups and include the full list.
#auto-select-group = true
# Configuration files that will be applied per user connection or
# per group. Each file name on these directories must match the username
# or the groupname.
# The options allowed in the configuration files are dns, nbns,
# ipv?-network, ipv4-netmask, rx/tx-per-sec, iroute, route, no-route,
# explicit-ipv4, explicit-ipv6, net-priority, deny-roaming, no-udp,
# keepalive, dpd, mobile-dpd, max-same-clients, tunnel-all-dns,
# restrict-user-to-routes, user-profile, cgroup, stats-report-time,
# mtu, idle-timeout, mobile-idle-timeout, restrict-user-to-ports,
# split-dns and session-timeout.
#
# Note that the 'iroute' option allows to add routes on the server
# based on a user or group. The syntax depends on the input accepted
# by the commands route-add-cmd and route-del-cmd (see below). The no-udp
# is a boolean option (e.g., no-udp = true), and will prevent a UDP session
# for that specific user or group. The hostname option will set a
# hostname to override any proposed by the user. Note also, that, any
# routes, no-routes, DNS or NBNS servers present will overwrite the global ones.
#config-per-user = /etc/ocserv/config-per-user/
#config-per-group = /etc/ocserv/config-per-group/
# When config-per-xxx is specified and there is no group or user that
# matches, then utilize the following configuration.
#default-user-config = /etc/ocserv/defaults/user.conf
#default-group-config = /etc/ocserv/defaults/group.conf
# The system command to use to setup a route. %{R} will be replaced with the
# route/mask, %{RI} with the route in CIDR format, and %{D} with the (tun) device.
#
# The following example is from linux systems. %{R} should be something
# like 192.168.2.0/255.255.255.0 and %{RI} 192.168.2.0/24 (the argument of iroute).
#route-add-cmd = "ip route add %{R} dev %{D}"
#route-del-cmd = "ip route delete %{R} dev %{D}"
# This option allows to forward a proxy. The special keywords '%{U}'
# and '%{G}', if present will be replaced by the username and group name.
#proxy-url = http://example.com/
#proxy-url = http://example.com/%{U}/
# This option allows you to specify a URL location where a client can
# post using MS-KKDCP, and the message will be forwarded to the provided
# KDC server. That is a translation URL between HTTP and Kerberos.
# In MIT kerberos you'll need to add in realms:
# EXAMPLE.COM = {
# kdc = https://ocserv.example.com/KdcProxy
# http_anchors = FILE:/etc/ocserv-ca.pem
# }
# In some distributions the krb5-k5tls plugin of kinit is required.
#
# The following option is available in ocserv, when compiled with GSSAPI support.
#kkdcp = "SERVER-PATH KERBEROS-REALM PROTOCOL@SERVER:PORT"
#kkdcp = "/KdcProxy KERBEROS.REALM [email protected]:88"
#kkdcp = "/KdcProxy KERBEROS.REALM [email protected]:88"
#kkdcp = "/KdcProxy KERBEROS.REALM tcp@[::1]:88"
#
# The following options are for (experimental) AnyConnect client
# compatibility.
# This option will enable the pre-draft-DTLS version of DTLS, and
# will not require clients to present their certificate on every TLS
# connection. It must be set to true to support legacy CISCO clients
# and openconnect clients < 7.08. When set to true, it implies dtls-legacy = true.
cisco-client-compat = true
# This option allows to disable the DTLS-PSK negotiation (enabled by default).
# The DTLS-PSK negotiation was introduced in ocserv 0.11.5 to deprecate
# the pre-draft-DTLS negotiation inherited from AnyConnect. It allows the
# DTLS channel to negotiate its ciphers and the DTLS protocol version.
#dtls-psk = false
# This option allows to disable the legacy DTLS negotiation (enabled by default,
# but that may change in the future).
# The legacy DTLS uses a pre-draft version of the DTLS protocol and was
# from AnyConnect protocol. It has several limitations, that are addressed
# by the dtls-psk protocol supported by openconnect 7.08+.
dtls-legacy = true
# Client profile xml. A sample file exists in doc/profile.xml.
# It is required by some of the CISCO clients.
# This file must be accessible from inside the worker's chroot.
# Note that enabling this option is not recommended as it will allow
# the worker processes to open arbitrary files (when isolate-workers is
# set to true).
#user-profile = /path/to/file.xml
#Advanced options
# Option to allow sending arbitrary custom headers to the client after
# authentication and prior to VPN tunnel establishment. You shouldn't
# need to use this option normally; if you do and you think that
# this may help others, please send your settings and reason to
# the openconnect mailing list. The special keywords '%{U}'
# and '%{G}', if present will be replaced by the username and group name.
#custom-header = "X-My-Header: hi there"
# An example virtual host with different authentication methods serviced
# # by this server.
#
# [vhost:www.example.com]
# auth = "certificate"
#
# ca-cert = ../tests/certs/ca.pem
#
# # The certificate set here must include a 'dns_name' corresponding to
# # the virtual host name.
#
# server-cert = ../tests/certs/server-cert-secp521r1.pem
# server-key = ../tests/certs/server-key-secp521r1.pem
#
# ipv4-network = 192.168.2.0
# ipv4-netmask = 255.255.255.0
#
# cert-user-oid = 0.9.2342.19200300.100.1.1
#
it works fine on openconnect client(all of supported os) but for cisco anyconnect it only works on v4.6 but for later versions anyconnect client can't reach server ("Connection attempt has timed out. Please verify Internet conectiviy" as log says). since downgrading app version is not available on ios devices I need to somehow config the server to be compatible with cisco anyconnect client v5. do you have any clues about problem with cisco anyconnect new versions?
