• June 23, 2018, 04:03:29 PM
Welcome, Guest. Please login or register. Registration is free.
Did you miss your activation email?

Author Topic: VLANS and Trunk  (Read 2510 times)

0 Members and 1 Guest are viewing this topic.

Offline jfwebber

  • Rookie
  • **
  • Posts: 3
VLANS and Trunk
« on: March 30, 2016, 02:51:52 PM »
I have a stack of 4850GTS-PWR+ that MLT to a Cisco 5548UP.  I am allowing all VLANs across the trunk.  The trunk ports are configured to tagAll.  The issue I am having is when I add a host on the Cisco 5548UP on VLAN 1 (192.168.1.x) it is unable to communicate with any other device on VLAN 1 on the stack of 4850's.  I am being told by my Cisco guy that the issue is I am tagging VLAN 1 on the 4850 side of the trunk and it should be untagged.  I can I untag just VLAN 1.  Thanks for any assistance.


Offline Telair

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 962
Re: VLANS and Trunk
« Reply #1 on: March 30, 2016, 04:42:09 PM »
That doesn't make a lot of sense.  The point of having a tagged port(s) is to be able to move all the VLAN's over it.  Avaya switches by default put all ports in VLAN 1 when there is no configuration, but otherwise VLAN 1 holds no special significance.  If it is tagged on the Cisco side it should be tagged on the Avaya side as well.

Offline Flintstone

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 953
Re: VLANS and Trunk
« Reply #2 on: March 31, 2016, 04:44:03 AM »
I believe that Cisco specify VLAN 1 as the default access VLAN on a trunk port so is untagged?

CheerZ

Offline WillyHe2

  • Rookie
  • **
  • Posts: 4
Re: VLANS and Trunk
« Reply #3 on: April 05, 2016, 07:47:12 AM »
On Cisco by default vlan 1 traffic is forward untagged on a tagged interface, all other vlan's are tagged.
You can configure an AVAYA switch to do the same by configuring "untagPvidOnly" on the interface(s) and configure "pvid" vlan = 1, check also that "filteruntaggedframes" is NOT enabled.
WillyHe
ACE FX #90

Offline jfwebber

  • Rookie
  • **
  • Posts: 3
Re: VLANS and Trunk
« Reply #4 on: April 05, 2016, 07:50:26 AM »
On Cisco by default vlan 1 traffic is forward untagged on a tagged interface, all other vlan's are tagged.
You can configure an AVAYA switch to do the same by configuring "untagPvidOnly" on the interface(s) and configure "pvid" vlan = 1, check also that "filteruntaggedframes" is NOT enabled.

Thanks WillyHe2.  I do have untagPvidOnly on the interfaces.  I will check that filteruntaggedframes is not enable and pvid vlan=1 is configured.

Offline jfwebber

  • Rookie
  • **
  • Posts: 3
Re: VLANS and Trunk
« Reply #5 on: April 06, 2016, 12:16:45 PM »
This is getting stranger.  The arp table on the Cisco 5548UP now has entries for mac addresses on VLAN1 from the Avaya.  However, I still am unable to communicate from a device on VLAN1 on the Cisco to any device on VLAN1 on the Avaya side.  I'm stumped   ???

Offline WillyHe2

  • Rookie
  • **
  • Posts: 4
Re: VLANS and Trunk
« Reply #6 on: April 06, 2016, 02:15:50 PM »
Is vlan 1 configured on the Uplink of the AVAYA switch?
Port pvid vlan id. is only for ingress, for egress you have to configure vlan's in the General vlan configuration (if using Graphical interface) or eg "vlan member add 1 1/48,2/48".
WillyHe
ACE FX #90

Offline aschi

  • Rookie
  • **
  • Posts: 1
Re: VLANS and Trunk
« Reply #7 on: April 09, 2016, 06:40:44 AM »
Just remembering, that i had similar issues.
Since i am not used in the Nortel/Avaya-World, i didn't really understand, when the PVID getts tagged and when not.
My way to solve this, was by telling the Cisco to tag all VLANs.

This can be done by:
- switchport trunk tag native
  --> only on some switch-models, not all support this command
        Hint: on some boxes, this command is global, so it has effect to all trunks!
workaround for the other models:
switchport trunk native vlan <X>
 --> Set <X> to a unused VLAN. this has the effect of tagging all (used) VLANs.

Offline WillyHe

  • Rookie
  • **
  • Posts: 2
  • 0090
Re: VLANS and Trunk
« Reply #8 on: April 11, 2016, 03:02:05 AM »
For me on AVAYA switches its simple.
1 - "UntagAll" means AL traffic is untagged send out.
2 - "TagAll" means AL traffic is send out tagged (also pvid vlan traffic).
3 - "UntagPvidOnly" means AL traffic is send out tagged except pvid vlan traffic (I think conform default Cisco behavior).
4 - "TagPvidOnly" means AL traffic is send out UNtagged except pvid vlan traffic.

VLAN port members are configured in common VLAN configuration.

Then there are parameters to configure at port level.
- "FilterUnregisteredFrames" means ingress tagged packets with a vlan id not configured on that port are dropped (default enabled) applies to point 2 & 3.
- "DiscardUntaggedFrames" means all untagged packets are dropped (default disabled), it is advised to enable this on "TagAll" ports.
- "PVIDvlan" means untagged and unknown traffic is accepted in this vlan, "FilterUnregisteredFrames" and "DiscardUntaggedFrames" overrule this configuration.

Hope this clarifies the problem.