Modifying MTU Size
IPSec and ESP add headers and trailers to a normal IP packet, which can lead to a packet being fragmented. The best practice is to set the maximum transmission unit (MTU) size as large as possible that will not cause a packet to be fragmented. To change the MTU size, choose Start, Programs, Cisco Systems VPN Client, Set MTU.
Cisco has recommendations, by operating system, for the MTU size. Access the release notes for the VPN Client version that you are using.
MTU size options are Default, 576, 1400, and Custom. The default MTU size is about 1420 bytes. If you select Custom, you can enter any MTU size in the field provided. |
Get SECUR Exam Cram™ 2 (Exam 642-501) now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.