I have a C4006, NmpSW 7.4, currently it has one VLAN - VLAN1, with a "set int sc0 1 172.16.0.9/255.255.0.0".
I want to split the X4448 in slot 6 into a second VLAN, VLAN 10, to "share" some Gigabit copper ports with a second switch - a C5000, its VLAN 1.
The C5000, NmpSW 6.3 has 3 VLANS, VLAN 1, 2 & 3, with connections from these VLANs to a 4000 router and has "set int sc0 1 192.168.8.40 255.255.255.0". It has a X4428-GB-RJ45 module, h/w ver 1.5 in slot 3.
I believe I should be able to add a second VLAN to the C4006, call it VLAN 10, allocate it 6/33 - 48. Take a cross-over cable from port 6/33 to the C5000's slot 3/1 port.
I've tried this on a test system and I note that on power up the C4006 issues an error message "native VLAN mismatch detected on port 6/33". When I do a "sh cdp nei" I note there is an asterisk next to the Port ID 3/1 for the C5000 connection port.
Is what I've proposed "safe" and what if any "gotcha's" are there
Essentially what you have done is bridge vlan 1 on the cat5k with vlan 10 on the cat4k.
If this is your intention then there is nothing wrong with that.
To stop the "CDP native vlan mismatch" message just disable cdp on that port using the "set cdp disable" command. The only reason that message is showing is because the cat4k is sending CDP messages saying that its port belongs to vlan 10 and the cat5k is sending CDP messages saying its port belongs to vlan 1.
But I'd try to test your configuration in channel mode ON.
I think when all ports are in VLANx on one switch and all ports are in VLANy on the other switch, ports in on mode do not exchange PAgP packets and the EtherChannel should work. If not, I'd try to disable CDP on the ports involved.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...