1 Cisco's implementation of the DTLS protocol unfortunately does not
2 comply with the relevant standards. OpenSSL 0.9.8m or newer, and
3 1.0.0-beta2 or newer, contain a compatibility mode which allows
4 interoperation with Cisco's servers.
6 As long as you are using a current version of OpenSSL, you have nothing
7 to worry about -- everything should work optimally.
9 Without a suitable OpenSSL, the openconnect client will fall back to
10 passing packets over the HTTPS connection. This will still work OK, but
11 will suffer quite a lot if your connection has packet loss. For details
12 of why that happens, see http://sites.inka.de/~W1011/devel/tcp-tcp.html
14 If you insist on using ancient buggy versions of OpenSSL, these are the
15 patches you require if you want DTLS to work:
17 For versions of OpenSSL earlier than 0.9.8m, you'll need the Cisco
18 compatibility support:
19 http://cvs.openssl.org/chngview?cn=18037
21 For versions of OpenSSL earlier than 0.9.8j, a couple of other DTLS
22 bug-fixes are also required:
23 http://cvs.openssl.org/chngview?cn=17500
24 http://cvs.openssl.org/chngview?cn=17505