02-16-2023 04:24 AM
Hi,
I´m dealing with GETVPN and I´ve a question regarding the output of "show crypto ipsec sa"...
the ACL on the KS is configured the following way:
permit ip 172.16.0.0 0.3.255.255 192.168.0.0 0.0.255.255
permit ip 192.168.0.0 0.0.255.255 172.16.0.0 0.3.255.255
why does the crypto ipsec output on the GM show´s the encrypted- and decrypted packets in different sections/lines?
local ident (addr/mask/prot/port): (172.16.0.0/255.252.0.0/0/0)
remote ident (addr/mask/prot/port): (192.168.0.0/255.255.0.0/0/0)
#pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0
#pkts decaps: 271179882, #pkts decrypt: 271179882, #pkts verify: 271179882
local ident (addr/mask/prot/port): (192.168.0.0/255.255.0.0/0/0)
remote ident (addr/mask/prot/port): (172.16.0.0/255.252.0.0/0/0)
#pkts encaps: 255682246, #pkts encrypt: 255682246, #pkts digest: 255682246
#pkts decaps: 0, #pkts decrypt: 0, #pkts verify: 0
03-04-2023 08:28 AM
I make review some GETVPN and find that Cisco mention about the using ACL for encrypt data and effect of permit ip any any in number of SA in GM,
so can you confirm that the KS push ACL with
permit ip 172.16.0.0 0.3.255.255 192.168.0.0 0.0.255.255
permit ip 192.168.0.0 0.0.255.255 172.16.0.0 0.3.255.255
instead of
permit ip any any
03-04-2023 10:17 AM
I don`t use a permit ip any any configuration in the Crypto-ACL on the KS, so yes - I can confirm that the KS pushes the ACL that way to the GMs
permit ip 172.16.0.0 0.3.255.255 192.168.0.0 0.0.255.255
permit ip 192.168.0.0 0.0.255.255 172.16.0.0 0.3.255.255
and for each line a dedicated SA is build, that`s the "issue" I´m facing
03-04-2023 06:16 PM
I run lab and add two ACL line
permit ip 10.0.0.0 0.0.0.255 20.0.0.0 0.0.0.255
permit ip 20.0.0.0 0.0.0.255 10.0.0.0 0.0.0.255
and I get as you get to SA one encrypt and other decrypt
so as I mention before this BECUASE asymmetric behave because we not add permit ip any any
IOU2#show crypto ipsec sa
interface: Ethernet0/0
Crypto map tag: mhm-1, local addr 110.0.0.2
protected vrf: (none)
local ident (addr/mask/prot/port): (20.0.0.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (10.0.0.0/255.255.255.0/0/0)
Group: mhm-1
current_peer 0.0.0.0 port 848
PERMIT, flags={}
#pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0
#pkts decaps: 2, #pkts decrypt: 2, #pkts verify: 2
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0
#pkts not decompressed: 0, #pkts decompress failed: 0
#send errors 0, #recv errors 0
protected vrf: (none)
local ident (addr/mask/prot/port): (10.0.0.0/255.255.255.0/0/0)
remote ident (addr/mask/prot/port): (20.0.0.0/255.255.255.0/0/0)
Group: mhm-1
current_peer 0.0.0.0 port 848
PERMIT, flags={}
#pkts encaps: 4, #pkts encrypt: 4, #pkts digest: 4
#pkts decaps: 0, #pkts decrypt: 0, #pkts verify: 0
#pkts compressed: 0, #pkts decompressed: 0
#pkts not compressed: 0, #pkts compr. failed: 0
#pkts not decompressed: 0, #pkts decompress failed: 0
#send errors 0, #recv errors 0
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide