Hello network exparts.
I have a problem to get MAC address from Catalyst swiches using Net-SNMP.
"snmpwalk -v 2c -c communityname switchname .220.127.116.11.18.104.22.168.3.1.1" does not answer some range of MAC addresses. The version of snmpwalk is 5.6.1 and 5.7.
Suppose hexadecimal number XX is in range 20 <= XX <= 7e, if all XX of MAC address XX:XX:XX:XX:XX:XX is in this range, Catalyst switches do not answer this MAC address via SNMP, but I can get the address by command line "show mac address-table"
I made ARP packet by Linux arping command "arping -0 -s 20:20:20:20:20:20 -p DST-IP-address" ( -s switch means SRC-MAC address) , but 20:20:20:20:20:20 is not obtaind by snmpwalk. But when I tried "arping -0 -s 20:20:20:20:7f:20 -p DST-IP-address", snmpwalk replies "Hex-STRING: 20 20 20 20 7F 20".
This test is done on Vlan 1 (Native), I tried VLAN-indexed "snmpwalk -v 2c -c communityname@1 switchname .22.214.171.124.126.96.36.199.3.1.1", but no improvement.
I only checked Catalyst IOS version 15.0(1)SE3 (2960,2960G,2960S,3750X) and 12.2(55)SE6 (3750G). But I think all of IOS-15.0 and IOS-12.X have this problem.