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6850 config clarification

Posted: 05 Mar 2018 23:49
by jagzeer
Hello guys,

I have an alcatel switch 6850 which I find some odd config.

Normally for cisco switch, if we can only configure the interface as access OR trunk.

But apparently in Alcatel, I found this both configuration exist in the switch.

vlan 10 port default 1/1 >>>>>>>>> this command makes the switch access port and assigned the vlan, if im not mastaking.

But I also see the same port being used to 802.1Q.

! 802.1Q :
vlan 4 802.1q 1/1 "TAG PORT 1/19 VLAN 4"
vlan 5 802.1q 1/1 "TAG PORT 1/19 VLAN 5"
vlan 6 802.1q 1/1 "TAG PORT 1/19 VLAN 6"

What is the impact of this? What will be the role of this port if these are the config.

Thanks in advance.

Regards

Re: 6850 config clarification

Posted: 06 Mar 2018 00:06
by jagzeer
Update:

I was reading the manual and found the answer. In alcatel, the ports can support both untagged and tag packets.

But i still dont understand the logic for this use. If you can use trunk the ports then just add the all the vlans in the tag port. (no use ]

Let say, switch A tagging the vlans (ex. 4,5,6) of course switch B also will tag those vlans(4,5,6) to match.

Regards

Re: 6850 config clarification

Posted: 06 Mar 2018 01:43
by silvio
the default vlan is like the native vlan. There is always one default vlan. All incoming 802.3-frames without vlan-tag will be forwarded to this default vlan. Per default tagged packets will be droped. Every 802.1q-tagged vlan has to be allowed at the ports. There is no "allow-all" tagged packets.
regards
Silvio

Re: 6850 config clarification

Posted: 06 Mar 2018 05:21
by priyanjan
jagzeer wrote:Hello guys,

I have an alcatel switch 6850 which I find some odd config.

Normally for cisco switch, if we can only configure the interface as access OR trunk.

But apparently in Alcatel, I found this both configuration exist in the switch.

vlan 10 port default 1/1 >>>>>>>>> this command makes the switch access port and assigned the vlan, if im not mastaking.

But I also see the same port being used to 802.1Q.

! 802.1Q :
vlan 4 802.1q 1/1 "TAG PORT 1/19 VLAN 4"
vlan 5 802.1q 1/1 "TAG PORT 1/19 VLAN 5"
vlan 6 802.1q 1/1 "TAG PORT 1/19 VLAN 6"

What is the impact of this? What will be the role of this port if these are the config.

Thanks in advance.

Regards
! 802.1Q :
vlan 4 802.1q 1/1 "TAG PORT 1/19 VLAN 4"
vlan 5 802.1q 1/1 "TAG PORT 1/19 VLAN 5"
vlan 6 802.1q 1/1 "TAG PORT 1/19 VLAN 6"

In above senario, you are assigning vlan to a trunk port and that port is 1/1. What ever with in brackets are just a description.

Sent from my Nexus 6P using Tapatalk


Re: 6850 config clarification

Posted: 06 Mar 2018 06:06
by jagzeer
Hi, Silvio

Thanks for the clarification. However this scenario no longer exist in 6860 running in AOS 8.4.1.141.R03.

If port assigned to a default then cannot assign to trunk or vice versa.

Re: 6850 config clarification

Posted: 06 Mar 2018 11:08
by silvio
In R7/R8 switches is the same behavior - only other commands to use it.
vlan xx member port|linkagg x/x/x tagged|untagged
At Alcatel there is no port-type like at cisco. You say which vlans are allowed at this port - tagged or untagged.
regards
Silvio

Re: 6850 config clarification

Posted: 06 Mar 2018 22:07
by jagzeer
Thanks Silvio. I just tested again and yes same behavior