Supported protocols and extension headers

The residential firewall distinguishes between known and unknown protocols or known and unknown extension headers.

Unknown protocols create or match flows based only on Layer 3 information. For a known protocol, the firewall inspects Layer 4 information to create or match flows more precisely. The following known protocols are supported:

• TCP

• UDP

• ICMPv6

Known extension headers are allowed by the firewall and processing continues on the remainder of the packet. The following extension headers are treated as known:

• Hop-by-hop (0)

• Fragment Header (44)

• Authentication Header (51)

• Destination Options (60)

• Shim Header (140)