Normal router traffic, routing updates, router configuration, Trivial File Transfer Protocol (TFTP), file transfers to a server, and HTTP access are subject to data manipulation, eavesdropping, and rerouting attacks.

A routing protocol can be authenticated by sending an MD5 hash of a password instead of sending the clear text password.

  • RIPv2, OSPF, EIGRP, and BGP support the MD5 hashes for authentication.
  • The MD5 hash is a 128 bit/16 byte fingerprint, or message digest.