1760 router hang when Ethernet WAN link above 3Mbps

[asoka]

HI, I have many 1760 routers with built in VPN module, but this router special, soon after WAN link upgrade from 2Mbps to 4Mbps it start hanging when wan link utilisation goes high, we change the hardware, means swap the router with a another similar model. This one with 3 P2P IPSEC tunnels , most of the CPU taken by encrypt process, so I down graded the encryption to DES as a workaround. But still when WAN link goes high router hangs.

Any one with any good suggesions pls, I attach the tech-support for review

[asoka]

Hi Edison,

I think we nail the problem, thanks to you

You have direct me to correct direction, I didnt worry much about the Half duplex thing cos there was no errors, but I managed to get the interface info from ISP side of the conenction , there were millions of CRC errors and other errors, so I hardcoded to 100/Full

Now there is no errors on the link.

What happen with this remote site was, when link utilisation goes up, users feel the slowness of the link, I beleive it was due to CRC and other errors. And user use to reset the router saying it was OK after reset, they never chk other things,

I manage to ge the customer yo Telnet to the router when it hang, that means router never hang, only the INTERFACE hang.

Now no issues for a day or so, will monitor the situ.

I think problem solved.

What happen was when ISP upgrade the link from 2Mbps to 4Mbps they didnt worry about check ing our side of the link speed and duplex.

Once again , Thanks for your help on this

Cheers