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New Member

IOS VPN to 3Com SuperStack 3

I configured the Cisco side of a VPN between and 806 and a 3Com SuperStack 3 firewall. The tunnel comes without issue and you CAN pass traffic through it, however the latency and througput are unbearable. Imagine a telnet taking 15 seconds to paint a dozen lines. If I simply open up a hole in the IOS FW and telnet through it, things fly. The latency only occurs when using the VPN. I've knocked everything down to single des, md5 and proc is ~5% at the most. I've never seen a VPN just work bad. It typically either works or it doesn't.

Any suggestions would be appreciated. Anyone ever go IOS to a SuperStack before?



Re: IOS VPN to 3Com SuperStack 3

could it be a mtu issue? how are ping times though it?

New Member

Re: IOS VPN to 3Com SuperStack 3

mtu is 1492 on the Cisco side, but I'm not sure about the 3Com side, though other site to site IPSec VPNs terminate on it. Ping times are generally good (less than 100 ms) when they make it through, but I drop about 10% of pings going from the 3Com side to the cisco side, but none going from the cisco side to the 3Com side. Being that I'm using 64 byte packets going from the 3Com side, I have my doubts about mtu being a problem. This one has me quite stumped.