Traceroute Question

[Patrick McHenry]

Hi,

I'm a bit confused with the output of traceroute and ping on our Core switch. There is a printer on our network that is not always reachable. Sometimes we can ping it and sometimes we can't. It seems that we can always ping it from a device on the same VLAN but, devices on other VLANs can only sometimes ping it. Here is some output:

NCR6509#ping 170.117.aa.aaa

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 170.117.aa.aaa, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
NCR6509#traceroute 170.117.aa.aaa

Type escape sequence to abort.
Tracing the route to 170.117.aa.aaa

  1  *  *  *
  2  *  *  *
  3  *  *  *
  4  *  *  *
  5  *  *

NCR6509#sh ip cef 170.117.aa.aaa

170.117.aa.aaa/32, version 192237, epoch 0, connected, cached adjacency 170.117.aa.aaa

0 packets, 0 bytes
  Flow: AS 0, mask 22
  via 170.117.aa.aaa, Vlan2, 0 dependencies
    next hop 170.117.aa.aaa, Vlan2
    valid cached adjacency

                                        "Device MAC"   "int VLAN 2 MAC"

NCR6509#traceroute mac aaaa.aaaa.aaaa bbbb.bbbb.bbbb
Error: Mac found on multiple vlans.
Layer2 trace aborted.

Do you need more info?

Any ideas? Thanks, Pat.

[John Peek]

When you do a mac address traceroute, you need to use a mac address of another host on that vlan. I have found that it won't work if you try to use the switches interface mac address, because it will use the same mac address for each vlan interface. Also posting configs might help. And have you done cable testing? Start at layer 1 and work your way up.