5 Configuring Interfaces214 Voyager Reference Guide18. (Optional) Define the cost of the tunnel. Enter this cost in the METRIC editbox. This shows the route preference. Leave this as the default unlessthere are many other multicast tunnels present in your network.19. Click A PPLY.20. Perform steps 1 through 13 with addresses reversed on the exit point forthe multicast tunnel. In this example, the ISP has already done this for us.21. Ensure that DVMRP is running on all interfaces (Ethernet, ATM, FDDI)on which the multicast is to be received (See “Configuring DVMRP” ).ARP Table EntriesChanging ARP Global Parameters1. Click C ONFIG on the home page.2. Click the ARP link under the Interfaces section.3. Enter the keep time (in seconds) in the KEEP TIME field in the GlobalARP Settings section.Keep time specifies the time, in seconds, to keep resolved dynamic ARPentries. If the entry is not referenced and not used by traffic after the giventime elapses, the entry is removed. Otherwise, a request is sent again toverify the MAC address. The range of the Keep Time value is 1 to 86400seconds with a default of 14400 seconds (4 hours).4. Enter the retry limit in the RETRY L IMIT field in the Global ARP Settingssection.The Retry Limit specifies the number of times to retry ARP requests untilholding off requests for the holdoff time, which is 20 seconds. Retryrequests occur at a rate of up to once per second. The range of retry limitis 1 to 100 and the default value is 3.5. If your network configuration requires it, click the button to enable theappliance to accept multicast ARP replies.
