09-30-2020 01:05 PM
I am configuring a new Cisco edge switch stack, and temporarily I am trunking this stack through another edge switch back to my core switch (no spare fiber pairs to use to trunk directly). This is how they're configured (lots of extraneous stuff removed):
**2960X Edge Stack** vtp mode transparent vlan 10 (old data subnet, 10.1.10.0/24) vlan 1000 (management subnet, 10.255.10.0/24) vlan 1080 (new data subnet, 10.1.80.0/24) int gi1/0/48 (trunk to 3560 edge switch) switchport mode trunk switchport trunk native vlan 1000 switchport trunk allowed vlan 10,1000,1080 spanning-tree portfast network int gi3/0/30 (edge port) switchport mode access switchport access vlan 1080 spanning-tree portfast edge ip routing ip route 0.0.0.0 0.0.0.0 10.255.10.254 **3560 Edge Switch** vtp mode transparent vlan 10 vlan 1000 vlan 1080 int gi0/3 (edge port) switchport mode access switchport access vlan 1080 spanning-tree portfast int gi0/20 (trunk to 2960 edge stack) switchport mode trunk switchport trunk encapsulation dot1q switchport trunk native vlan 1000 switchport trunk allowed vlan 10,1000,1080 spanning-tree portfast int gi0/49 (trunk to 9300 core switch) switchport mode trunk switchport trunk encapsulation dot1q switchport trunk native vlan 1000 switchport trunk allowed vlan 10,1000,1080 spanning-tree portfast ip routing ip route 0.0.0.0 0.0.0.0 10.255.10.254 **9300 Core Switch** vtp mode transparent vlan 10 vlan 100 (server subnet, 10.1.0.0/24) vlan 1000 vlan 1080 int te1/1/2 (trunk to 3560 edge switch) switchport mode trunk switchport trunk native vlan 1000 switchport trunk allowed vlan 10,1000,1080 int Vlan10 ip address 10.1.10.254 255.255.255.0 ip helper-address 10.1.0.1 int Vlan100 ip address 10.1.0.254 255.255.255.0 int Vlan1000 ip address 10.255.10.254 255.255.255.0 int Vlan1080 ip address 10.1.80.254 255.255.255.0 ip helper-address 10.1.0.1 ip routing
A device connected to an edge port on the 2960X in VLAN1080 (gi3/0/30 in this case) cannot get a DHCP address, and even with a statically-assigned address can't ping the gateway (10.1.80.254). If I put that port in VLAN10 instead, it will get a DHCP address and can ping everything as expected.
A device connected to an edge port on the 3560 in VLAN1080 will get a DHCP address in the correct scope (10.1.80.0/24) and can ping the gateway (10.1.80.254).
What seems to be happening is that the 3560 is maybe stripping the 802.1Q tags when traffic is traversing from the 2960X to the 9300, but I don't see any reason it should be doing that. Can anyone suggest what's happening here and how to fix it?
09-30-2020 01:55 PM
Hi there,
From each of the three switches mentioned can you share the full output of: sh spanning vlan 1080
cheers,
Seb.
09-30-2020 02:05 PM
If the device just acting as Layer 2 all way up to 2960X - where the end device connected.
you do not need ip routing. and what is the management IP , you need just default-gateway. (not this not solution, just want to correct here)
2960X - not sure what license you have i see some limitation vlan numbering here.
is this possible to rename 1080 VLAN to VLAN 80 all the way and test ?
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