You change the configuration of a tunnel by using the following command syntax:
$ dladm modify-iptun -a [local|remote]=addr,... tunnel-link
You cannot modify the type of an existing tunnel. Thus, the –T type option is not allowed for this command. Only the following tunnel parameters can be modified:
Specifies literal IP addresses or host names that correspond to the local address and the remote tunnel address. Depending on the type of tunnel, you specify either only one address, or both local and remote addresses. If you are specifying both local and remote addresses, you must separate the addresses with a comma.
IPv4 tunnels require local and remote IPv4 addresses to function.
IPv6 tunnels require local and remote IPv6 addresses to function.
6to4 tunnels require a local IPv4 address to function.
For persistent IP tunnel data-link configurations, if you are using host names for addresses, these host names are saved in the configuration storage. During a subsequent system boot, if the names resolve to IP addresses that are different from the IP addresses that were used when the tunnel was created, then the tunnel acquires a new configuration.
If you are changing the tunnel's local and remote addresses, ensure that these addresses are consistent with the type of tunnel that you are modifying.
To change the name of the tunnel link, use the dladm rename-link command rather than the modify-iptun command as follows:
$ dladm rename-link old-tunnel-link new-tunnel-link
To change tunnel properties such as the hoplimit or encaplimit, use the dladm set-linkprop command rather than the modify-iptun command.
The following example consists of two procedures. First, the local and remote addresses of the IPv4 tunnel vpn0 are temporarily changed. When the system is later rebooted, the tunnel reverts to using the original addresses. The second command shows how to change the hoplimit of vpn0 to 60.
$ dladm modify-iptun -t -a local=203.0.113.149,remote=192.0.2.3 vpn0 $ dladm set-linkprop -p hoplimit=60 vpn0