Enterasys Networks X-PeditionTM manual Vlan Processing VLAN-enabled Ethernet to WAN Interfaces

IP Routing Protocols

Figure 5-5 VLAN Ethernet to Fast/GigabitEthernet Topology

	2				IP Routing Table
					1.2.3.0/24 F1.1
					3.3.2.0/24 F2		IP 3.2.3.4/24
				VLAN 1200	9.9.9.0/24 F2 (Static)
				IP 1.2.3.4/24	F2				3
							Ethernet	IP: 9.9.9.1
Ethernet		VLAN Tag		IP: 9.9.9.1	F1.1	Outgoing Ethernet frame
	1
Priority	CFI		VLAN: 1300
Incoming VLAN tagged frame

VLAN Processing: VLAN-enabled Ethernet to WAN Interfaces

In this scenario, shown in Figure 5-6, the XSR does not insert a VLAN tag in Ethernet frames because no VLAN is linked with the outgoing port (Serial 1).

Note: VLAN tags cannot be assigned to a WAN interface - they are relevant only for XSR FastEthernet and GigabitEthernet interfaces.

Figure 5-6 VLAN Ethernet to WAN Interfaces Topology

2	IP Routing Table
	1.2.3.0/24 F1.1
	3.3.2.0/24 Serial 1
VLAN 1200	9.9.9.0/24 Serial 1 (Static)

				IP 1.2.3.4/24		Serial 1
								PPP	IP: 9.9.9.1
Ethernet		VLAN Tag		IP: 9.9.9.1	F1.1		Outgoing Serial frame
	1					IP 3.2.3.4/24
						PPP encapsulation
Priority	CFI		VLAN: 1200
Incoming VLAN tagged frame

3

VLAN Processing: WAN Interface to a VLAN-enabled Ethernet Interface

In this scenario, as shown in Figure 5-7, a VLAN tag is inserted since a VLAN ID (1200) is associated with the outgoing VLAN sub-interface (FastEthernet 1.1). The packet will be forwarded to IP address 9.9.9.1 of the next-hop router. For traffic which did not enter the XSR from a VLAN sub-interface, the priority bits are set to 0 (lowest level).

XSR User’s Guide 5-21