Error in OpenVPN Logs on pfSense

[pfSense_fan 181]

A number of users of pfSense have all shared a single error in our logs ever since the 4096 bit config upgrade.

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write UDPv4: No buffer space available (code=55)

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​We have been searching, testing and tweaking trying to figure it out since then. Although we made our systems run better, we never quite got rid of the error. Finally I came accross an answer at the pfSense forums and also the same conclusion at a tunnelblick forum.

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This is what happens when you setup broken routing, where your client gets a route to the server IP where it's connecting, within the VPN, and tries to access the server IP by using the tunnel. It has to be able to reach the server outside the tunnel not within it, and basically loops traffic and causes chaos. Don't push or setup routes on your client inside the tunnel for the IP it has to reach outside the tunnel.

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​This is affecting many pfSense users. Staff, is there any option we can add to our configs to prevent this?

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​https://forum.pfsense.org/index.php?topic=40405.msg208614#msg208614

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​https://code.google.com/p/tunnelblick/issues/detail?id=44#c16

 

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:36 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 17:15:28 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:57:34 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:57:34 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:57:34 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:57:34 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:57:34 openvpn[.....]: write UDPv4: No buffer space available (code=55)

Apr 29 16:34:14 openvpn[.....]: Initialization Sequence Completed

Apr 29 16:34:14 openvpn[.....]: /sbin/route add -net 10.30.0.1 10.30.x.x 255.255.255.255

Apr 29 16:34:14 openvpn[.....]: NOTE: unable to redirect default gateway -- Cannot read current default gateway from system

Apr 29 16:34:14 openvpn[.....]: /usr/local/sbin/ovpn-linkup ovpnc2 1500 1558 10.30.x.x 10.30.x.x init

Apr 29 16:34:14 openvpn[.....]: /sbin/ifconfig ovpnc2 10.30.x.x 10.30.x.x mtu 1500 netmask 255.255.255.255 up

Apr 29 16:34:14 openvpn[.....]: do_ifconfig, tt->ipv6=1, tt->did_ifconfig_ipv6_setup=0

Apr 29 16:34:14 openvpn[.....]: TUN/TAP device /dev/tun2 opened

Apr 29 16:34:14 openvpn[.....]: TUN/TAP device ovpnc2 exists previously, keep at program end

Apr 29 16:34:14 openvpn[.....]: ROUTE: default_gateway=UNDEF

Apr 29 16:34:14 openvpn[.....]: Could not retrieve default gateway from route socket:: No such process (errno=3)

Apr 29 16:34:14 openvpn[.....]: OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified

Apr 29 16:34:14 openvpn[.....]: OPTIONS IMPORT: route options modified

Apr 29 16:34:14 openvpn[.....]: OPTIONS IMPORT: --ifconfig/up options modified

Apr 29 16:34:14 openvpn[.....]: OPTIONS IMPORT: LZO parms modified

Apr 29 16:34:14 openvpn[.....]: OPTIONS IMPORT: timers and/or timeouts modified

Apr 29 16:34:14 openvpn[.....]: PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1,dhcp-option DNS 10.30.0.1,comp-lzo no,route 10.30.0.1,topology net30,ping 10,ping-restart 60,ifconfig 10.30.x.x 10.30.x.x'

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[pfSense_fan 181]

I will be testing this config option for the next few days to see if it fixes this issue.
 

 

--route-nopull

When used with --client or --pull, accept options pushed by server EXCEPT for routes and dhcp options like DNS servers.

When used on the client, this option effectively bars the server from adding routes to the client's routing table, however note that this option still allows the server to set the TCP/IP properties of the client's TUN/TAP interface.