I don't have SUP7 to test, but it works on SUP6 and SUP32, I would presume SUP7 retains this functionality.
I've tested between JNPR M320 <-> SUP32, and 'vlan mapping JNPR SUP32' works just fine.
There is no need for QinQ, what the QinQ option does is it adds top tag to one particularly tag. So switchport vlan mapping 1042 dot1q-tunnel 42 would map incoming [1042] stack to [42 1042] stack.
As opposed to switchport vlan mapping 1042 42 which maps incoming dot1q Vlan [1042] to dot1q Vlan [42].
JNPR M320 config:
{master}[edit interfaces ge-0/1/0 unit 1042]
user@m320# show
vlan-id 1042;
family inet {
address 10.42.42.1/24;
}
{master}[edit interfaces ge-0/1/0 unit 1042]
user@m320# run show interfaces ge-0/1/0
Physical interface: ge-0/1/0, Enabled, Physical link is Up
Interface index: 135, SNMP ifIndex: 506
Description: B: SUP32 ge5/1
Link-level type: Flexible-Ethernet, MTU: 9192, Speed: 1000mbps, BPDU Error: None,
MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled,
Auto-negotiation: Enabled, Remote fault: Online
Device flags : Present Running
Interface flags: SNMP-Traps Internal: 0x4000
CoS queues : 8 supported, 8 maximum usable queues
Current address: 00:12:1e:d5:90:7f, Hardware address: 00:12:1e:d5:90:7f
Last flapped : 2013-02-19 09:14:29 UTC (19w6d 21:12 ago)
Input rate : 4560 bps (5 pps)
Output rate : 6968 bps (4 pps)
Active alarms : None
Active defects : None
Interface transmit statistics: Disabled
SUP32 config:
SUP32#show run int giga5/1
Building configuration...
Current configuration : 365 bytes
!
interface GigabitEthernet5/1
description F: M320 ge-0/1/0
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
switchport vlan mapping enable
switchport vlan mapping 1042 42
mtu 9216
bandwidth 1000000
speed nonegotiate
no cdp enable
spanning-tree portfast edge trunk
spanning-tree bpdufilter enable
end
SUP32#show ru int vlan42
Building configuration...
Current configuration : 61 bytes
!
interface Vlan42
ip address 10.42.42.2 255.255.255.0
end
SUP32#sh int GigabitEthernet5/1 vlan mapping
State: enabled
Original VLAN Translated VLAN
------------- ---------------
1042 42
SUP32#sh int vlan42
Vlan42 is up, line protocol is up
Hardware is EtherSVI, address is 0005.ddee.6000 (bia 0005.ddee.6000)
Internet address is 10.42.42.2/24
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not supported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:09, output 00:01:27, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
L2 Switched: ucast: 17 pkt, 1920 bytes - mcast: 0 pkt, 0 bytes
L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast
L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes
38 packets input, 3432 bytes, 0 no buffer
Received 21 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
26 packets output, 2420 bytes, 0 underruns
0 output errors, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
And
SUP32#ping 10.42.42.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.42.42.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
SUP32#sh arp | i 10.42.42.1
Internet 10.42.42.1 12 0012.1ed5.907f ARPA Vlan42
SUP32#show mac address-table dynamic address 0012.1ed5.907f
Legend: * - primary entry
age - seconds since last seen
n/a - not available
vlan mac address type learn age ports
------+----------------+--------+-----+----------+--------------------------
Active Supervisor:
* 450 0012.1ed5.907f dynamic Yes 0 Gi5/1
* 50 0012.1ed5.907f dynamic Yes 0 Gi5/1
* 40 0012.1ed5.907f dynamic Yes 0 Gi5/1
* 42 0012.1ed5.907f dynamic Yes 5 Gi5/1
user@m320# run ping 10.42.42.2 count 2
PING 10.42.42.2 (10.42.42.2): 56 data bytes
64 bytes from 10.42.42.2: icmp_seq=0 ttl=255 time=0.495 ms
64 bytes from 10.42.42.2: icmp_seq=1 ttl=255 time=0.651 ms
--- 10.42.42.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.495/0.573/0.651/0.078 ms
{master}[edit interfaces ge-0/1/0 unit 1042]
user@m320# run show arp no-resolve |match 10.42.42.2
00:05:dd:ee:60:00 10.42.42.2 ge-0/1/0.1042 none
Is there a reliable way to infer the switch "Base ethernet MAC Address" from receiving such a CDP interface MAC Address, so that I can use that "Base ethernet MAC Address" as a globally unique identifier for the switch device equipment on the network?
You can't determine the base ethernet mac from CDP without guessing or assumptions about how Cisco behaves today (as well as future behavior). On the other hand, if all you want is a unique identifier, use the Chassis serial number; however, that would require polling the CDP source for entPhysicalSerialNum... a small price to eliminate guesswork.
entPhysicalSerialNum has the added bonus of working across many of Cisco's current platforms.
Sample SNMP walk of entPhysicalSerialNum:
[mpenning@tsunami ~]$ snmpbulkwalk -OXsq -v 2c -c ciscoro -m ENTITY-MIB \
172.16.1.200 entPhysicalDescr
entPhysicalDescr[1] 2650 chassis
entPhysicalDescr[2] 2600 Chassis Slot
entPhysicalDescr[3] C2600 Mainboard
entPhysicalDescr[4] 2600 DaughterCard Slot
entPhysicalDescr[5] 2600 DaughterCard Slot
entPhysicalDescr[6] AIM Container Slot 0
entPhysicalDescr[7] 2600 Chassis Slot
entPhysicalDescr[8] One port Fastethernet TX
entPhysicalDescr[9] AmdFE
entPhysicalDescr[10] AmdFE
[mpenning@tsunami ~]$ snmpbulkwalk -OXsq -v 2c -c ciscoro -m ENTITY-MIB \
172.16.1.200 entPhysicalSerialNum
entPhysicalSerialNum[1] JAB05290Z8Q
entPhysicalSerialNum[2]
entPhysicalSerialNum[3] yyyyyyyyyyy
entPhysicalSerialNum[4]
entPhysicalSerialNum[5]
entPhysicalSerialNum[6]
entPhysicalSerialNum[7]
entPhysicalSerialNum[8] 25809045
entPhysicalSerialNum[9]
entPhysicalSerialNum[10]
[mpenning@tsunami ~]$
Best Answer
A quick google search turns up the doc "Supported Platforms for Unique MAC Address Configuration on VLAN or L3 Interfaces for Catalyst Switches" which learns us that both the default behaviour as well as the potential to change the MAC address, are very different depending on the switch model (and in some cases, depending on the IOS version).
So, look up your model there but I think it is safe to assume that if
Switch(config-if)# mac-addressdoes not work, changing the MAC address is not supported on that platform.Potential workaround
If "standby mac-address" is supported on your platform, you can configure HSRP with a virtual IP address linked to a virtual MAC. In other words if you currently have
Then you can change this to e.g. :
Where 10.0.0.254 is a previously unused address. Since I'm not sure of the reason for your request, it may or may not be important to note that an ARP request for 10.0.0.254 will still reveal the switch's BIA (burnt-in address) so if you're doing this e.g. to avoid fingerprinting, it may not be optimal.