IPSEC interoperability matrix
This
openswan interoperability matrix
may help, since Endian Firewall uses Openswan as ipsec implementation.
It contains also howto's about how to set it up with openswan.
Additional vendors:
Fortinet:
Article on Fortinet Knowledge Center
Ciphers reported working:
only
3DES works
Authentication reported working: PSK
Linksys:
Howto in
Endian Kowledge Base
Ciphers reported working: 3DES
Authentication reported working: PSK