configure isis mesh

configure isis [vlan all | {vlan} vlan_name] mesh [block-none | block-all | block-group group_id]


This command configures LSP flooding behavior for the specified interface.

Syntax Description

vlan all

Applies the configuration to all IS-IS This command is available on the ExtremeSwitching X440-G2, X450-G2, X460-G2, X465, X590, X620, X670-G2, X690, X695, X870, 5320, 5420, 5520 series switches.s.


Specifies a single VLAN to which the configuration applies.


Disables LSP blocking.


Blocks all LSPs. No LSPs are flooded out of the selected interface.


Blocks LSPs that contain the specified group ID.


Specifies a group ID number. The range is 1 to 4294967295.



Usage Guidelines

In a mesh environment, which is a set of fully interconnected point-to-point interfaces, LSP flooding can generate N2 PDUs because no router can tell which routers have and have not received the flooded LSP. By carefully selecting the links over which LSPs are flooded, traffic can be greatly reduced at the cost of some resiliency. Using mesh group IDs instead of a full block (the block-all option) allows a finer granularity of control.


The following command configures blocking on SJvlan for group 5:

configure isis SJvlan mesh block-group 5


This command was first available in ExtremeXOS 12.1.

Platform Availability

This command is available on platforms with a Core or Premier license as described in the ExtremeXOS and Switch Engine 31.7 Feature License Requirements document.