Hi
I have just created a site to site GRE tunnel between two Mikrotik Routers HQ and branch office. When I try to reach branch network from HQ and other way around I am able to get ICMP response but with ping drops around 45% to 55%. Upon checking status in tunnel interface there are no drops.Can some one help with troubleshooting the issue. Remote terminal is using satellite internet with latency of 800ms . ICMP response from HQ Public IP to Branch public IP doesn’t have drops. Can somebody help to troubleshoot?
I am using Clamp TCP MSS and Allow fastpath. How can i check if drops are due to fragmentation. Tunnel interface MTU set to 1476. Is there anyway to set MSS.
Clamp TCP MSS has no effect on pings, so if even pings are being dropped, the reason is not MTU - especially if you didn’t specify large ping packets.
800 ms latency is close to the 1 s after which the ping process normally stops waiting for an echo response and sends another echo request, so it could be that the tunnel processing adds that small bit which makes the difference (ping between public IPs has no loss but ping inside the tunnel has 50 % loss).
So as the very first step I’d try to run the ping with interval=2s .
Hi
Thanks for reviewing and helping me to resolve the issue. Please see ICMP response in attachment.
HQ LAN Interface IP : 172.18.4.253/24
Branch LAN Interface IP: 192.168.20.1/24
I think I can, but from the screenshots and the wording in your previous post, I’ve concluded it has already been resolved. The pictures show occasional packet loss, not 50 % as you wrote in the OP, and there were only statements, no questions. So what’s the actual state of the art, and what have I missed in the screenshots?
