01-06-2009 08:28 AM - edited 03-06-2019 03:16 AM
We have to 2960g'S and from switch 0 I can't ping switch 1 and people on switch 1 can't access the proxy server on switch 0
I can't see anything wrong with this config please help
and as there was only one cable going between the old switches there is only one going between the new switches and it happens to be going from sw0/47 to sw1/48
Solved! Go to Solution.
01-07-2009 08:02 AM
Richard. Thats cool. But any idea why the portchannel did not work ? Layer 2 on portchannel was fine, but no layer 3 access ? were you able to troubleshoot that ?
Anyway, great to see that you have solved the issue...
Raj
01-06-2009 09:25 AM
From what I can see, the problem you might have is with how the port-channel is setup. Currently, on both switches, you are using ports Gi0/47 and 48 in the port-channel.
If you don't plan on using port channel, I would remove that portion of the configuration and just have normal trunk connections between sw0/47 to sw1/48.
You can remove the port-channels by doing the following on both switches:
interface range Gigabitethernet 0/47-48
no channel-group 1 mode on
no interface port-channel 1
The interfaces will be just normal trunk ports now, since the command "switchport mode trunk" was already there.
01-06-2009 09:27 AM
Please post output of
1) sh int trunk
2) sh ip int brief
3) sh cdp neigh
from both switches.
Jon
01-06-2009 09:50 AM
As the switches are over 4,000 miles away from me and there isn't a console cable going to SW1 I can only sh the output from SW0
(I will have access to SW1 tommorow but I need to figure out what part of the config I messed up on)
if simpily removing the port-channel would work I'll remove it from both but we want the port-channel for speed and reliability(although the 2nd cable wasn't connected yet)
01-06-2009 10:23 AM
And I still can't ping 172.18.18.3 from ether the server or sw0
01-06-2009 10:35 AM
Hey richard
Are you getting the mac-address/ARP details of 18.3 from Switch 0 ?? Is the layer 2 communication through ? Might be there is another PC or device with the same IP address, and there could be a IP clash ! just guessing.. Troubleshoot starting from layer 1, then 2, and atlast 3 ! Are there any logs, in "show log" output ??
Also, add the command "switchport encapsulation dot1q" on the trunk interfaces, to force dot1q.. In anycase, your native vlan is 1, and the packets would go untagged, just like an access port....
Hope this helps..
Raj
01-06-2009 10:49 AM
the 2960G's don't have the command "switchport encapsulation dot1q" (as they can only do Dot1Q)
and in the output of show Mac address-table shows multiple mac addresses from interface PO1
01-06-2009 10:52 AM
does it show the mac-address of 18.3 from Switch 0 , in the ARP table? If yes, can you see if that particular ARP is forwarded out of PO 1, using the show mac-address table command ?
show arp for 18.3, take the ARP and give a show mac-addr table..
Raj
01-06-2009 10:56 AM
I don't know off hand a mac address for SW1(18.3) and till tommorow I can't connect to the Command line
as for IP addresses We've used the same ones that the former switches used (which were swaped out) so there shouldn't be an IP conflict
users on sw1 can't reach users on sw0
01-06-2009 10:59 AM
After pinging (unsuccessfully of course) 18.3 from SW0 then quickly doing a SH arp it shows incomplete as the mac address for 18.3
01-06-2009 11:08 AM
Can you configure switchport mode access, and switchport access vlan 1 on the gig0/47 port of switch 0 connecting to Switch 1, for troubleshooting purpose , and remove trunk ? Let it act as a normal access port and try to reach VLAN 1's ip address on the second switch !
in anycase, we will have to wait till u get access to second switch !
Raj
01-06-2009 11:01 AM
No.. what I was asking you to check is, if you have an ARP table entry for 172.18.18.3 on Switch 0.. If this doesnt exist, it is a layer 2 issue... You can probably do a clear ARP on switch 0, to make sure the IP 18.3 doesnt point to the older switch's MAC !! ARP will re-build again, and populate the mac address table !
If you dont have any ARP for 18.3 on Switch 0 (using the show arp command), it is tough to troubleshoot, unless you get access to second switch...
Raj
01-06-2009 11:08 AM
There is no entry on SW0 for 18.3 in the arp table
but if I try to ping 18.3 an entry shows up for a few seconds (but is listed as incomplete)
01-06-2009 11:00 AM
If he removes the portchannel then one link will become blocked because that creates a built in loop so it will be a single link carrying traffic between them . Is layer 1 ok ? Verify with "show interface status" , 47 and 48 should show connected. Does a show interface trunk look right , though this can be deceiving when the trunks and channels are forced on . That being said even if the trunk was working who is doing the layer 3 routing as the 2960's are layer 2 only and need a layer 3 device to route between the different vlans.
01-06-2009 11:03 AM
glen.. layer 1 seems to be fine.. had a look at CDP !
SW0#sh cdp n
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
SW1 Gig 0/47 150 S I WS-C2960G Gig 0/48
it does show the second switch connected.. cdp is fine.. need access to second switch i guess..
Raj
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