So, let's say I have an ISR G1 router, and a Lan-to-Lan IPSec tunnel built. On the outside interface(WAN) I have an MTU of 1260, with the 'ip mtu 1260' command. Now if I put this command in, the max IPSec (ESP) packet will be 58 bytes, and with tunnel mode you add an additional 20 bytes as well, for the new IP header, since the original or encapsulation within ESP, encrypted and authenticated.
So this would come to 1338 with my math. Now if I ping from the source of my WAN to the remote IP (Extended Ping) with 1338 as the size, and DF-bit set I don't get any successful pings. If I do an Extended Ping with the byte size of 1178 which is (1100+50+20) I get successfully pings. So would it be wise to get ride of 'ip mtu 1260' and put 'ip mtu 1100' ?
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...