> [mailto:[EMAIL PROTECTED] On Behalf Of Tom Storey > > On 18/12/2007, at 7:42 AM, Paul - Talk Talk wrote: > > > We have upgrade our lease line from 4mb copper to 10mb fibre which > > meant we > > had to change our router. > > > > The old router was a Cisco 2620 and the new Router is a Cisco 1841. > > > > Between the Cisco Router and our Cisco 3550 layer three switch is a > > bandwidth management box, which is an Allot NetEnforcer AC-402. > > > > On the old the old set-up using the Cisco 2620 everything > worked fine. > > > > On the new set-up with the Cisco 1841 we are seeing a lot of CRC > > errors > > until the whole thing falls over. > > > >> From our side nothing has changed except the router which was > >> supplied by > > the ISP. > > > > We did find out that the FE0/0 interface on the Cisco 1841 was set > > to auto, > > but this has now been set to Full Duplex 100mb which > matches the Allot > > NetEnforcer. > > > > Taking the NetEnforcer out and connecting to the Cisco 1841 > directly > > to the > > Cisco 3550 stops the errors, but as said before switching back to > > the Cisco > > 2620 also stops the errors. > > > > On one particular PC I have cannot auto negotiate and cannot > be set to > 100/full without producing errors. I have to run it in 100 half. At > least this one is only a PC. Its got a Broadcom NIC. > > My suggestion would be, if you can spare two ports on the switch, to > create a VLAN and stick the two interfaces that would > normally connect > directly to each other into that VLAN. Otherwise, try > different cables > between the two, set the port to 100/half, and try different > interfaces if you can. > > I may have other issues with the PC above, such as a dodgy cable. I > havnt gone so far to test that out yet as its bandwidth requirements > are low, 100/half does just fine.
I can't imagine that running half-duplex is a good idea. I have had interfaces on the 28xx series (in particular with the HWIC ethernet) where they have had to be set to auto/auto on both sides to not produce errors. This includes connecting to a Cisco switch on the other end. Since your upstream is 10Mb you can probably also get away with running 10/Full, although it makes increasing bandwidth in the future a bit more cumbersome. Thanks, Josh _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
