Allied-telesis AT-9724TS Bedienungsanleitung PDF herunterladen (Seite 101)

Static ARP Table

The Address Resolution Protocol (ARP) is a TCP/IP protocol that converts IP addresses into physical addresses.This table allows network managers to view, define,

modify and delete ARP information for specific devices.

Static entries can be defined in the ARP Table.When static entries are defined, a permanent entry is entered and is used to translate IP address to MAC

addresses.

To open the

Static ARP Table open the Configuration folder, and then open the Layer 3 IP Networking folder and click on the Static ARP

Table

link.

Figur

e 6- 93. Static ARP Settings window

To add a new entry, click the

Add button, revealing the following screen to configure:

Figure 6- 94. Static ARP Table – Add a New Entry window

The following fields can be set:

Parameter Description

IP Address

The IP address of the ARP entry.

MAC Address The MAC address of the ARP entry.

After entering the IP Address and MAC Address of the Static ARP entry, click Apply to implement the new entry.To completely clear the Static ARP

Settings

, click the Clear All button.To delete an entry located in the Static ARP Settings window, click the corresponding 8 under the Delete heading.

RIP

The Routing Information Protocol is a distance-vector routing protocol.There are two types of network devices running RIP – active and passive.Active devices

advertise their routes to others through RIP messages, while passive devices listen to these messages. Both active and passive routers update their routing tables

based upon RIP messages that active routers exchange. Only routers can run RIP in the active mode.

Every 30 seconds, a router running RIP broadcasts a routing update containing a set of pairs of network addresses and a distance (represented by the number of

hops or r

outers betw

een the advertising router and the remote network). So, the vector is the network address and the distance is measured by the number of

routers between the local router and the remote network.

RIP measur

es distance b

y an integer count of the n

umber of hops from one network to another.A router is one hop from a directly connected network, two

hops from a network that can be reached through a router, etc.The more routers between a source and a destination, the greater the RIP distance (or hop

count).

Ther

e ar

e a f

w rules to the r

outing table update pr

ocess that help to impr

ve performance and stability.A router will not replace a route with a newly learned

one if the new route has the same hop count (sometimes referred to as ‘cost’). So learned routes are retained until a new route with a lower hop count is

learned.

When learned routes are entered into the routing table, a timer is started.This timer is restarted every time this route is advertised. If the route is not

advertised for a period of time (usuall

y 180 seconds), the route is removed from the routing table.

RIP does not have an explicit method to detect routing loops. Many RIP implementations include an authorization mechanism (a password) to prevent a router

from learning erroneous r

outes fr

om unauthorized r

outers.

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Allied Telesyn AT-9724TS High-Density Layer 3 Stackable Gigabit Ethernet Switch