We should replace the underscore with a hyphen.
1.4 output:
vyos@r1-roll:~$ show vpn ipsec sa Connection State Uptime Bytes In/Out Packets In/Out Remote address Remote ID Proposal ------------------ ------- -------- -------------- ---------------- ---------------- ----------- ---------------------------------- peer_192-0-2-1_vti up 16m28s 0B/0B 0/0 192.0.2.1 N/A AES_CBC_256/HMAC_SHA1_96/MODP_1024
1.3 output more preferable/readable:
vyos@r4-1.3:~$ show vpn ipsec sa Connection State Uptime Bytes In/Out Packets In/Out Remote address Remote ID Proposal ------------------------- ------- -------- -------------- ---------------- ---------------- ----------- ---------------------------------- peer-192.0.2.2-tunnel-vti up 17m37s 0B/0B 0/0 192.0.2.2 N/A AES_CBC_256/HMAC_SHA1_96/MODP_1024