AES slow when compared to 3DES
I'm using two 2811 routers to create a network to network GRE IPSec VPN using shared keys and esp-3des to encrypt traffic. When I transfer a very large file across the VPN tunnel the transfer takes place at around 40Mbps (the physical connection between the routers is currently a 10/100 switch). I changed the encryption algorithm to esp-aes 128, and the same file now transfers at only 4Mbps. Is this to be expected? I had read that AES was more "computationaly efficient" than 3DES, so naturally I expected it to be faster not 1/10 the speed. By the way, the routers have VPN accelerator cards and an MTU of 1514 is set on the tunnel interfaces. Any ideas?
read more and respond »Posted 5 years ago by Chris in Cisco Systems
