3Com WX3000 Procedure for the Switch to Judge Packet Protocol, Encapsulation Formats

Procedure for the Switch to Judge Packet Protocol

Figure 1-9Procedure for the switch to judge packet protocol

Ethernet II	0x0600 to 0xFFFF
encapsulation

Receive packets

Type(Length)			Invalid packets
		0x05DD to 0x05FF	that cannot be
	field
			matched
	0 to 0x05DC

Match the type value

802.3 raw	Both are FF
encapsulation

802.2/802.3
encapsulation
Control	Value is not 3
field
Value is 3
dsap/ssap	Both are AA
value

Invalid packets that cannot be matched

802.2SNAP encapsulation

Other values

802.2LLC

encapsulation

Match the dsap/ssap value

Match the type value

Encapsulation Formats

Table 1-1 lists the encapsulation formats supported by some protocols. In brackets are type values of these protocols.

Table 1-1Encapsulation formats

Encapsulation	Ethernet II		802.3 raw		802.2 LLC		802.2 SNAP
Protocol
IP (0x0800)	Supported		Not supported		Not supported	Supported
IPX (0x8137)	Supported	Supported		Supported		Supported
AppleTalk	Supported		Not supported	Not supported		Supported
(0x809B)

Implementation of Protocol-Based VLAN

The switching engines of the devices assign the packet to the specific VLAN by matching the packet with the protocol template.

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