Avaya Configuring ATM Half-Bridge Services Bedienungsanleitung PDF herunterladen (Seite 28)

Configuring ATM Half-Bridge Services

1-10

308611-14.00 Rev 00

Removing Bridge Table Entries

AHB removes an existing table entry whenever it adds a new entry with the same

source MAC address, ATM port, and VPI/VCI number. AHB also removes a table

entry when it receives a DHCPRELEASE message (assuming that the source IP

address-to-ATM port/VPI/VCI mapping is correct). If the entry being removed is

on the original slot, all other slots that have received copies are notified to remove

those entries. When AHB removes the last host entry on a network, it deletes the

corresponding route from the IP routing table.

Replacing Bridge Table Entries

If the bridge table contains a bridge entry that was learned on a different circuit/

PVC, and AHB learns another IP packet with the same IP address on a different

circuit and VCID, then AHB replaces the old entry with the new entry. New

entries that AHB learns in unsecure mode do not replace existing entries learned

in secure mode, even if AHB learned them on different slots.

Using Source-Based Routing

The network provider can use source-based routing to ensure that the packet sent

from a CPE host travels to the correct ISP gateway first, regardless of its

destination address. The ISP gateway can be an edge router directly connected to

an AHB router via a WAN interface (frame relay, PPP) or a router located within

the ISP’s domain. This option allows multiple links connecting the AHB router

with the ISP network. If one link or edge router fails, traffic from ATM-attached

hosts is routed via another edge router.

You use source-based routing by configuring an IP traffic filter on the ATM

interface. You must specify traffic filter criteria and a traffic filter action. The

traffic filter criteria is the range of source IP addresses allocated to CPE hosts

belonging to a single ISP. You must configure a separate traffic filter for each

range of source addresses that get assigned to the ATM-attached hosts by an ISP.

These filters must be installed on every AHB circuit.

The traffic filter action is “forward to next hop,” which identifies the ISP’s

gateway device. The next-hop address in the traffic filter need not be a directly

attached host. If it is not a directly attached host, AHB accesses the routing table

to determine the directly attached host to which the packets are sent.

1 2 ... 23 24 25 26 27 28 29 30 31 32 33 ... 93 94

Keine Kommentare

Avaya Configuring ATM Half-Bridge Services Bedienungsanleitung Seite 28