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c2821 Maximum Number of Vlans encap. dot1q

How many Vlans encapsulation dot1q does support an c2821 with 2 Gigabit Ethernet interfaces?

Thanks.

1 Accepted Solution

Accepted Solutions

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Mariano,

in a router each Vlan subif takes a row in the IDB = interface descriptor block.

the total of physical and logical interfaces on your router cannot be higher then the IDB size.

This number is dependent on platform and IOS version.

on a c2821 the IDB can be 512

I didn't find the number so you should be able to implement several subinterfaces on your router.

2821

900

see

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_tech_note09186a0080094322.shtml#idb_limits

I shouldn't go behind 20 subinterfaces per GE there are other factors to be considered like the size of the NIC MAC packet filter.

Hope to help

Giuseppe

View solution in original post

2 Replies 2

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Mariano,

in a router each Vlan subif takes a row in the IDB = interface descriptor block.

the total of physical and logical interfaces on your router cannot be higher then the IDB size.

This number is dependent on platform and IOS version.

on a c2821 the IDB can be 512

I didn't find the number so you should be able to implement several subinterfaces on your router.

2821

900

see

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_tech_note09186a0080094322.shtml#idb_limits

I shouldn't go behind 20 subinterfaces per GE there are other factors to be considered like the size of the NIC MAC packet filter.

Hope to help

Giuseppe

Giuseppe, thank you very much. It is that i was needed.

Mariano.

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