identifier (VCI) to multiplex the different channels over the physical link. The Ethernet
protocol type serves the same function within a VLAN as the logical link control (LLC)
subnetwork attachment point (SNAP) within a VC, to multiplex the different protocols
over the channel.
Figure 13: Use of VLANs to Multiplex Different Protocols over a Single Physical Link
ERX14xx models (rear view)
In a VLAN configuration, the router can send VLAN 0
tagged
or
untagged frames
.
All VLAN subinterfaces use the MAC address of the Ethernet interface over which
they are configured. However, some configurations, such as multiple IP over VLAN
subinterfaces, require that you connect many VLAN subinterfaces to a single device.
In these cases, the device uses the MAC address to identify and select the correct
VLAN to use. When the MAC address is the same for all VLANs, uneven load balancing
of traffic occurs. To ensure proper load balancing, you must assign unique MAC
addresses to the individual VLAN subinterfaces that are connected to the device. Any
ARP requests and responses generated for the IP address assigned to a VLAN
subinterface use this MAC address.
You must assign the MAC address when you configure the VLAN ID. If you change
the MAC address of the VLAN subinterface after you configure it, system errors can
occur. To change the MAC address, you must first remove the VLAN subinterface
and then reconfigure it.
For more information, see:
■
Chapter
Configuring IP
in
JUNOSe IP, IPv6, and IGP Configuration Guide
■
“Configuring Point-to-Point Protocol over Ethernet” on page 375
S-VLAN Overview
As described in “VLAN Overview” on page 169, VLANs permit multiplexing multiple
IP interfaces and PPPoE interfaces over a single physical Ethernet port by creating
VLAN subinterfaces. As specified in IEEE Standard 802.1q, the 12-bit VLAN identifier’s
tagged frames enables the construction of a maximum of 4096 distinct VLANs. In
an Ethernet B-RAS application environment, however, this VLAN limit is inadequate.
170
■
S-VLAN Overview
JUNOSe 11.1.x Link Layer Configuration Guide
Содержание JUNOSE 11.1.X - LINK LAYER CONFIGURATION 4-7-2010
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Страница 8: ...viii JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 26: ...xxvi List of Figures JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 34: ...2 Chapters JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 200: ...168 Monitoring Upper Level Protocols over Ethernet JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 230: ...198 Monitoring VLAN and S VLAN Subinterfaces JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 258: ...226 Monitoring 802 3ad Link Aggregation JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 334: ...302 Troubleshooting JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 394: ...362 Monitoring Multiclass MLPPP JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 406: ...374 Monitoring POS JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 468: ...436 Troubleshooting JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 498: ...466 Monitoring Bridged Ethernet JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 546: ...514 Monitoring Cisco HDLC JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 747: ...Part 2 Index Index on page 717 Index 715...
Страница 748: ...716 Index JUNOSe 11 1 x Link Layer Configuration Guide...
Страница 774: ...742 Index JUNOSe 11 1 x Link Layer Configuration Guide...