Vlan 1 tagging on routed switchport

[meconomou]

I have a pair of Cisco 6880 switches connected to an Aruba stack that I have configured for GLBP. I am having issues with getting these 2 switches to pass traffic. The Cisco switches are configured with routed ports and sub-interface vlan tags and the Aruba switch is just a trunk to each Cisco, tagges with vlan 99. However, when you look at the physical interface on the Cisco switch it is tagging vlan 1 and the sub-interface is tagging vlan 99.

Under command show interfaces on your Cisco… for port 5/9, we see vlan 1 is encapsulated:
TenGigabitEthernet5/9 is up, line protocol is up (connected)
Hardware is C6k 10000Mb 802.3, address is 5897.bdf1.c840 (bia 5897.bdf1.c840)
MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set

For the sub interface 5/9.99 we see vlan 99 is encapsulated:
TenGigabitEthernet5/9.99 is up, line protocol is up (connected)
Hardware is C6k 10000Mb 802.3, address is 5897.bdf1.c840 (bia 5897.bdf1.c840)
Description: TEST
Internet address is 192.168.99.1/24
MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 99.

If I set this up in a lab, the physical port shows:

GigabitEthernet1/0 is up, line protocol is up (connected)
Hardware is iGbE, address is 007b.691a.3804 (bia 007b.691a.3804)
Description: "To Aruba Switch"
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set

GigabitEthernet1/0.99 is up, line protocol is up (connected)
Hardware is iGbE, address is 007b.691a.3804 (bia 007b.691a.3804)
Internet address is 192.168.99.1/24
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA
ARP type: ARPA, ARP Timeout 04:00:00

Why would I get 2 different behaviors? Should I switch to SVI interfaces instead of routed ports?

[Reza Sharifi]

Are you connecting the Cisco switches to Aruba wireless controllers? Can you explain your topology?

Are the Cisco switches supposed to be layer-2 only?  Not sure why you are sub-interface while you can use SVIs with vlans.

HTH

[Georg Pauwen]

Hello,

what lab did you create this in ? In GNS3, the output is the same as what you posted first (encapsulated)...

[Dennis Mink]

not exactly sure what is is you are trying to achieve. are you sure you need vlans if you just define one of them? I mean why not use routed ports instead?

[Dennis Mink]

not exactly sure what is is you are trying to achieve. are you sure you need vlans if you just define one of them? I mean why not use routed ports instead?