VPN load traffic
here it is : in my company we're discussing about configuring vpn tunnels. We work with government and thus use its WAN. Nowadays we only use encrypted protocols, but would like to use snmp, ftp and other common uncyphered protocols.
The wan is only 128kbytes/s in some agencies, so I was wondering wether setting on VPN would increase the traffic load...
I know the main problem is usually cpu load, but in my case, that shouldn't be a problem because we've got recent machines.
Since we're on a private WAN, I think using low level encryption would be enough (simple des).
So question 1 :
Will des really be lighter than aes ? or does this affect only the cpu use ?
I know that a part of overhead will come from ISAKMP, but I thought configuring a 24 hours rotation time or so.
Thus question 2 is :
Is this a huge security hole, or does this sound acceptable ?