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Questions tagged [ipsec]

Questions relating to IPSEC VPN configuration, operation and troubleshooting specifically.

9
votes
2answers
10k views

In IPsec VPN, how is the pre-shared key encrypted?

I was doing IPsec VPN on ASA 8.0, and I understand a little about that. The initiator starts by sending its ISAKMP policy to the responder, and the responder sends back the matched policy. After that, ...
4
votes
2answers
3k views

Why do multi-line crypto ACL's create instability in VPN tunnels?

Why does using multiple sets of specific ip's to specific ip's in a crypto ACL - cause instability in VPN tunnels, please relate this to phase 2 SA's (IPSEC). Ex. 172.16.0.0 -> 10.0.0.0 172.17.0....
7
votes
1answer
12k views

Ipsec vpn, phase 2 unable to come up

I'm pretty sure I know the answer to this but I don't know how to implement it. Trying to setup an ipsec vpn from a Cisco 2811 to a linux box running openswan. So far I can get phase 1 up but ...
4
votes
1answer
2k views

IPSec site-to-site with/without NAT

I am connecting my office to a client's network via IPSec. The need is for me to connect directly to internal IPs on their network; there is no need for them to connect to any services on my internal ...
3
votes
1answer
1k views

How to keep an ASA tunnel up for lifetime?

We have a Cisco ASA and at the remote end I have no idea what the device is. This is what happening: When I send a packet or generate interesting traffic, it brings up the tunnel and everything ...
2
votes
1answer
288 views

ipsec vpn with preshared key p

I understood that three session keys are generated by diffi-helmen and nonces, in phase 1 msg 3 and msg 4 both exchanged diffi-helmen public key and generate shared secret key ,and shared secret key ...
1
vote
1answer
46 views

How to configure a distributed network for the replication? [closed]

I want to replicate data (music, video, photos, user's data) across different geographical networks. How to connect several networks into a single network to let nodes comunicate to each other? ...
0
votes
0answers
53 views

ASA - communication between 2 tunnels

I have two IPSEC tunnels with an ASA in the middle Site A - 10.20.4.0 /24 (65.176.80.84) Site B - 192.168.142.0 /24 ASA - 10.99.206.0 /24 (95.12.22.33 Site A - 10.20.4.0 /24 can reach the ASA and ...