Joined: 18 Mar 2014 Posts: 13879 Location: Netherlands
Posted: Fri Jul 19, 2024 6:12 Post subject:
Just came across this thread, I usually dwell in this forum
Thanks @KP69 for transferring this thread to the correct forum.
Unfortunately there is not enough information give a definitive answer to the question of the OP.
Start with sharing your router model and build number.
The OpenVPN client setup guide has a paragraph about trouble shouting but if you provide the following information we can better assist you:
• Enable "Syslogd" on Services page
• Add in OpenVPN Additional config: verb 5 and Save and Apply
• From the CLI (telnet/Putty) view/send openvpn log: grep -i openvpn /var/log/messages
• From the CLI (telnet/Putty) view/send: cat /tmp/openvpncl/openvpn.conf
• Post pictures of OpenVPN Setup page and Status page (whole page)
• Post content of Additional Config on OpenVPN Setup page
• For PBR send output of:
o ip rule show
o ip route show
o ip route show table 10
o cat /tmp/openvpncl/policy_ips
Joined: 18 Mar 2014 Posts: 13879 Location: Netherlands
Posted: Fri Jul 19, 2024 7:11 Post subject:
About DCO
This is from the troubleshooting guide:
Quote:
DCO (Data Channel Offload) connection problems after build 53787
DCO (Data Channel Offload) is present in DDWRT builds with kernel 4.4 and higher starting with build 53787.
It uses a special tun kernel module which uses the kernel to handle traffic instead of constantly switching to userspace, furthermore it can use multithreading.
This can speed up OpenVPN throughput up to 100 %.
DCO is not compatible with a number of options and if those are chosen DCO will be disabled so always review your log file.
Note that DCO will use DATA_V2 packets in P2P mode, therefore, this implies that peers must be running 2.6.0+ in order to have P2P-NCP which brings DATA_V2 packet support.
It is still a WIP and can cause hangs/restarts/connection problems especially on Kernel 4.X (OpenVPN only supports DCO on Kernel 5.x but BS has backported it to our Kernel 4.X), when in doubt disable it.
To disable DCO add in the OpenVPN additional config:
disable-dco
I read the forum to quickly, I don't notice the issue about DCO in newer builds.
I was used to have openvpn, with another dd-wrt build, that don't have this issue
I also try to put "disable-dco" on client's side ; but not from server ...
