This article discusses how the EX Series assigns MAC addresses, and the difference in how this is done before and after the release of Junos EX 11.3.
What is the MAC address assignment scheme for the EX Series, and what are the differences before and after the Junos EX 11.3 version?
All interfaces in 4200/3200 get a MAC address from the system MAC pool. Since every 3200 system is shipped with minimum of 64 addresses and there can be maximum of 64 interfaces of any time (ge, ae etc), the count is always considered to be 64. Thus, the pool is
system_mac_base to
system_mac_base + 64. The procedure is to start from base and go all the way up to 64, for every type of port on every device.
Logical interfaces such as VLAN are only assigned one MAC address per entire virtual connection.
Before Junos-EX 11.3
vlan interface system_mac_base
vme interface system_mac_base + 1
AE0 interface system_mac_base
AEn interface system_mac_base + n
ge-*/0/0 interface system_mac_base
ge-*/0/n interface system_mac_base + n
ge-*/1/0 interface system_mac_base + (number of ports on pic 0)
ge-*/1/n interface system_mac_base + (number of ports on pic 0) + n
After Junos-EX 11.3
vlan interface System_Mac_Base + (len - 1)
vme interface System_Mac_Base + (len - 1)
ae0……aeN interface with L2 Address family System_Mac_Base…… System_Mac_Base + N (with local bit set)
ae0……aeN interface with L3 Address family System_Mac_Base
ge-x/0/0……ge-x/0/N interface with L2 Address family System_Mac_Base…… System_Mac_Base + N (with local bit set)
ge-x/0/0……ge-x/0/N interface with AL Address family System_Mac_Base
ge-x/y/0……ge-x/y/N interface with L2 Address family Mac_Block_Base of FPC x + (sum of all ports in previous) …… Mac_Block_Base of FPC x + (sum of all ports in previous pics) + N
ge-x/0/0……ge-x/y/N interface with L3 Address family System_Mac_Base