Configure an ESP group on the Corporation-B router

An example of how to configure an ESP group on the Corporation-B router.

These steps configure the ESP group esp1 on the Corporation-B router.

Set the lifetime for the whole ESP group to match the setting being used by the Corporation-A router.
```
vyatta@CORPB# set security vpn ipsec esp-group esp1 lifetime 600
```
Set the ESP group encryption cipher to match the settings being used by the Corporation-A router.
```
vyatta@CORPB# set security vpn ipsec esp-group esp1 proposal 1 encryption aes256
```
Set the authentication mode to match the authentication mode set on the Corporation-A router and specify the IP address of the Corporation-A router.
```
vyatta@CORPB# set security vpn ipsec site-to-site peer 128.0.0.11 authentication mode pre-shared-secret
```
Set the pre-shared secret to match the secret set on the Corporation-A router and specify the IP address of the Corporation-A router.
```
vyatta@CORPB# set security vpn ipsec site-to-site peer 128.0.0.11 authentication pre-shared-secret HelloDolly
```
Specify the default ESP group for all tunnels to match the one specified on the Corporation-A router and specify the IP address of the Corporation-A router.
```
vyatta@CORPB# set security vpn ipsec site-to-site peer 128.0.0.11 default-esp-group esp1
```

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