vlan internal allocation policy ascending

[ssatishh08]

hi there,

I was just going throug one sample configuration n i came across this command

vlan internal allocation policy ascending

can some someone please tell me what does this command do n when do we use this command

thanks in advance

[ssatishh08]

u can find the attchment of this config .

[Jon Marshall]

Hi

The switch reserves a number of vlans for it's own internal use.

vlan internal allocation policy ascending means that it will start to allocate vlans from 1006 upwards.

If it was descending it would start at 4094 and work downwards.

HTH

Jon

[ssatishh08]

hey thanks for quick reply jon, i appreciate

but could you please elobarate more upon this.

vlan internal allocation policy ascending
!
vlan10,20,22-23,30,32,40-41,61-64,70,81-85,87-88,90,100,110-122,130
!
vlan 140,150,160,175,200-205,208-210,942

what does the commands following command

vlan internal allocation policy ascending

do. does it play ne part in allocation vlans mentioned above

thanks

[Jon Marshall]

Hi

The commands following the vlan internal line are the vlans that you have created on the switch. The vlan internal line does not affect these vlans that you create.

The internal vlans are vlans that the switch assigns itself. They are not normally visible on a "sh vlan".

If you want to see these use the following command

sh vlan internal usage

HTH

Jon

[ssatishh08]

cool, thanks jon

so that means these are the vlans which the switch uses for its internal operartion and switch does not assign ne physical ports to it.

please correct me if i'm wrong.

[Jon Marshall · Accepted solution]

Hi

yes, these vlans are for internal operation and are not configurable by you and most will not have physical ports associated with them. There could be physical ports assigned to them eg. from one of my switches

SZ-JFH-F00-DTE1#sh vlan internal usage

VLAN Usage

---- --------------------

1006 online diag vlan0

1007 online diag vlan1

1008 online diag vlan2

1009 online diag vlan3

1010 online diag vlan4

1011 online diag vlan5

1012 PM vlan process (trunk tagging)

1013 Control Plane Protection

1014 L3 multicast partial shortcuts for VPN 0

1015 Egress internal vlan

1016 Multicast VPN 0 QOS vlan

1017 IPv6 Multicast Egress multicast

1018 GigabitEthernet3/1

vlan 1018 has the gi3/1 port assigned to it. It is actually the trunk connection between the 2 6500 switches. But this has not stopped me using gi3/1 and i configured that port.

I guess the switch just uses it as a reference.

HTH

Jon