[Openswan Users] Simple configuration: ping OK, telnet fails

"Adrián R. Sanchez" adrian_sanchez at actionline.com.ar
Mon Mar 20 14:28:08 CET 2006

> IP routing is set up, and ping works, however telnet doesn't work. Does 
> anybody knows what's wrong here?

I had the same problem and found out that it was a fragmentation issue, 
which I solved with the following iptables line:

iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss=1358

This will force packets not to exceed 1358 bytes thus leaving space for 
the IPSec overhead and avoiding fragmentation, which might be the cause 
of your problem.


Adrián R. Sanchez
Dpto. de Tecnología

Actionline de Argentina S.A.
Viamonte 570 (C1053ABL)
Buenos Aires, Argentina
Tel.: +54 11 5093-3905

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