Few days ago I could see a user question about Linux analogue for Cisco "show mac-address-table" command. He wo'nt use the "arp"or "arp -a" command for some hidden reasons. And I think it may be interesting for other users.
name='more'>
The "arp" or "arp -a" command shows you mac-address table (MAC-interface maping) and ARP table (MAC-IP mapping) all-in-one. Cisco IOS devices, as networking equipment, show some more information and it contains VLAN id and entry type (static or dynamic).
Cisco output are below:
#sh mac address-table
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
All 0100.0ccc.cccc STATIC CPU
All 0100.0ccc.cccd STATIC CPU
<skipped>
All ffff.ffff.ffff STATIC CPU
10 0000.0c07.abcd DYNAMIC Gi0/1
20 000b.be68.bcde DYNAMIC Gi0/2
30 0013.6016.cdef DYNAMIC Gi0/3
<skipped>
Total Mac Addresses for this criterion: 67
#sh ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.100.10.11 0 3c4a.92b2.abcd ARPA Vlan10
Internet 10.100.20.28 162 b4b5.2fab.bcde ARPA Vlan20
But Linux "arp" and "arp -a" commands show us some another information:
# arp
Address HWtype HWaddress Flags Mask Iface
192.168.10.1 ether 00:50:56:c0:00:08 C eth0
192.168.10.2 ether 00:50:56:f2:83:0a C eth0
# arp -a
? (192.168.10.1) at 00:50:56:c0:00:08 [ether] on eth0
? (192.168.10.2) at 00:50:56:f2:83:0a [ether] on eth0
So you can see both ARP and MAC-address table in one output. It is not so rich as Cisco output but it is good enough.
But if you think that the "arp" output contains a lot of extra information you may parse it with "awk" command:
# arp | grep -v Address | awk ' { print $3,$5 } '
00:50:56:c0:00:08 eth0
00:50:56:f2:83:0a eth0
If you hate the "arp" or "awk" command you must
# brctl addbr 1
# brctl addif 1 eth0
# brctl showmacs 1
port no mac addr is local? ageing timer
1 00:0c:29:1f:cf:5a yes 0.00
1 00:50:56:c0:00:08 no 0.00
So I hope this information may be interesting and useful.
name='more'>
The "arp" or "arp -a" command shows you mac-address table (MAC-interface maping) and ARP table (MAC-IP mapping) all-in-one. Cisco IOS devices, as networking equipment, show some more information and it contains VLAN id and entry type (static or dynamic).
Cisco output are below:
#sh mac address-table
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
All 0100.0ccc.cccc STATIC CPU
All 0100.0ccc.cccd STATIC CPU
<skipped>
All ffff.ffff.ffff STATIC CPU
10 0000.0c07.abcd DYNAMIC Gi0/1
20 000b.be68.bcde DYNAMIC Gi0/2
30 0013.6016.cdef DYNAMIC Gi0/3
<skipped>
Total Mac Addresses for this criterion: 67
#sh ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.100.10.11 0 3c4a.92b2.abcd ARPA Vlan10
Internet 10.100.20.28 162 b4b5.2fab.bcde ARPA Vlan20
But Linux "arp" and "arp -a" commands show us some another information:
# arp
Address HWtype HWaddress Flags Mask Iface
192.168.10.1 ether 00:50:56:c0:00:08 C eth0
192.168.10.2 ether 00:50:56:f2:83:0a C eth0
# arp -a
? (192.168.10.1) at 00:50:56:c0:00:08 [ether] on eth0
? (192.168.10.2) at 00:50:56:f2:83:0a [ether] on eth0
So you can see both ARP and MAC-address table in one output. It is not so rich as Cisco output but it is good enough.
But if you think that the "arp" output contains a lot of extra information you may parse it with "awk" command:
# arp | grep -v Address | awk ' { print $3,$5 } '
00:50:56:c0:00:08 eth0
00:50:56:f2:83:0a eth0
If you hate the "arp" or "awk" command you must
- install bridge-utils,
- set the bridge,
- add interfaces to the bridge
- use "brctl showmacs" command
# brctl addbr 1
# brctl addif 1 eth0
# brctl showmacs 1
port no mac addr is local? ageing timer
1 00:0c:29:1f:cf:5a yes 0.00
1 00:50:56:c0:00:08 no 0.00
So I hope this information may be interesting and useful.
