Note: This procedure does not update /etc/llttab; therefore the change is not persistent across reboots unless /etc/llttab is modified. In addition this procedure should only be used during initial configuration or for testing.

Environment Sample:
2 node cluster.

more /etc/llthosts
0 sprs1950a0-28
1 sprs1950a0-27

2 Links
eth0 lowpri, eth1 hipri

/sbin/lltconfig -a list
Link 0(eth1):
 Node   0 sprs1950a0-28:  00:15:C5:E5:83:D6  permanent
 Node   1 sprs1950a0-27:  00:15:C5:E5:83:D1

Link 1 (eth0):
 Node   0sprs1950a0-28:   00:15:C5:E5:83:D8  permanent
 Node   1sprs1950a0-27:   00:15:C5:E5:83:D3


For this test purpose I will be removing eth1 hipri links and configuring them for UDP.

Step 1: Remove the current eth1 hipri link. From both nodes run.

/sbin/lltconfig -ueth1

Step 2: Get the IP and Broadcast information from the NIC's.

Note: Make sure the IP is configured on the NIC prior to configuring UDP over LLT.

On node 0:
ifconfig eth1|grep addr:
         inetaddr:10.0.0.1  Bcast:10.0.3.255  Mask:255.255.252.0
         inet6addr: fe80::215:c5ff:fee5:83d6/64 Scope:Link

On node 1:
ifconfig eth1|grep addr:
         inetaddr:10.0.0.2  Bcast:10.0.3.255  Mask:255.255.252.0
         inet6addr: fe80::215:c5ff:fee5:83d1/64 Scope:Link


Step 3: Configure the LLT link to use UDP.

On node 0:
lltconfig -t eth1 -d eth1 -b udp -I10.0.0.1 -B 10.0.3.255

On node 1:
lltconfig -t eth1 -d eth1 -b udp -I10.0.0.2 -B 10.0.3.255


Step 4. Verify that UDP is configured.

/sbin/lltconfig -a list
Link 0(eth1):
 Node   0 sprs1950a0-28:  10.0.0.1  permanent
 Node   1 sprs1950a0-27:  10.0.0.2

Link 1 (eth0):
 Node   0 sprs1950a0-28:  00:15:C5:E5:83:D8  permanent
 Node   1 sprs1950a0-27:  00:15:C5:E5:83:D3


/sbin/lltstat -l
LLT link information:
link0  eth1 on udp hipri
       mtu 8192, sap0x04bc, broadcast 10.0.3.255, addrlen 4
       txpkts1125  txbytes 108052
       rxpkts972  rxbytes 102568
       latehb 1  badcksum0  errors 0
link 1  eth0 on etherlowpri
       mtu 1500, sap 0xcafe, broadcast FF:FF:FF:FF:FF:FF, addrlen 6
       txpkts17254  txbytes 1774548
       rxpkts112794  rxbytes 5741352
       latehb9  badcksum 0  errors 0

Step 5. Use tethereal to view and verify traffic over the wire is UDP.
Note: tethereal is a linux tool used to monitor network traffic. For more information/details on tethereal please see the man pages.

The command below will display network traffic over eth1and log the data to /root/log.out.
tethereal -i eth1 -w/root/log.out

The command below will read the data from/root/log.out
tethereal -r /root/log.out |grep UDP.
 2  0.062141     10.0.0.2 -> 10.0.0.1     UDP Source port:1212  Destination port: 1212
 3   0.063506    10.0.0.1 -> 10.0.0.2     UDP Source port: 1212  Destinationport: 1212
 7   0.562200     10.0.0.2 ->10.0.0.1     UDP Source port: 1212  Destination port:1212
 8   0.564400     10.0.0.1 ->10.0.0.2     UDP Source port: 1212  Destination port:1212
 9   0.631318     10.0.0.2 ->10.0.0.1     UDP Source port: 1212  Destination port: 1212
10   0.631550     10.0.0.1 -> 10.0.0.2     UDPSource port: 1212  Destination port: 1212