Buy or Renew
Buy or Renew
Duo Security forums now LIVE! Get answers to all your Duo Security questions. Learn more
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 
cancel
Start a conversation
1255
Views
5
Helpful
1
Replies

Cisco ASA cluster control link MTU

umeshunited
Beginner
Beginner

‎12-13-2019 02:18 AM - edited ‎02-21-2020 09:45 AM

What is the reason behind increasing MTU on CCL ( cluster control link)?

Is it because in the worst-case scenario where one of the boxes fails, CCL will be responsible for carrying heavy traffic ?

0 Helpful
1 Reply 1

nspasov
Cisco Employee
Cisco Employee

‎12-13-2019 08:33 AM

Hi there. Traffic is going through the CCL when one cluster member needs to forward packets for sessions that belong to another member. The redirected traffic adds an additional trailer. As a result, this can cause fragmentation. Consequently, you want the MTU of the CCL to be at least 100 bytes higher than the one set of your data interfaces. All of this is very well described in the Cisco Live session:

https://www.ciscolive.com/global/on-demand-library.html?search=cluster&search.event=ciscoliveus2019#/session/1542224329797001rye8

I hope this helps!

Thank you for rating helpful posts!

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Customers Also Viewed These Support Documents