Friday, December 11, 2015

Vlan considerations NX-OS

In this post, I want to bring forward a few items that should be taken under consideration in  Nexus OS when it pertains to vlans an design vlan-id details.

In cisco IOS and NX-OS , you have certain  internal vlan usage. So the full range of  vlan-IDs 1 thru 4094 are NOT always available. Outside of the vlans that are hardcoded for specific functions  ( i.e vlan IDs ; 1 1002-1005, 4095, etc...) you have to take in considerations of these vlan-ids.

So in NX-OS you need to know the default reserved vlan id ranges. The cmd cli show system vlan  reserved will provide this detail.







 The config mode will allow you to adjust this range but keep in mind you still will have  128 reserved vlan-ids.






Next, cisco has always had a 32 character or less naming convention for vlan names.

In NX-OS we can use cmd   system vlan long-name to allow for names longer than 32 character but most show commands will still limited the displayed output to 32characters.

 







 



If you define a vlan name longer than 32 characters, the switch will complain if you try to no out the command.












Ken Felix
NSE ( network security expert) and Route/Switching Engineer
kfelix  -----a----t---- socpuppets ---dot---com

     ^      ^
=(  @  @ )=
         o 
        /  \

No comments:

Post a Comment