MLAG Primary/Secondary roles
- MLAG peers ___ a primary and secondary status within an MLAG domain
- Initially, switch with the lowest system MAC is elected MLAG primary
- Primary and Secondary status determine Layer 2 protocol operation
- Also generate a Mlag System ID to be used for L2 operation
negotiate
MLAG Primary/Secondary roles
- MLAG peers negotiate a primary and secondary status within an MLAG domain
- Initially, switch with the ____ system MAC is elected MLAG primary
- Primary and Secondary status determine Layer 2 protocol operation
- Also generate a Mlag System ID to be used for L2 operation
lowest
MLAG Primary/Secondary roles
- MLAG peers negotiate a primary and secondary status within an MLAG domain
- Initially, switch with the lowest system MAC is elected MLAG primary
- Primary and Secondary status determine ___ protocol operation
- Also generate a Mlag System ID to be used for L2 operation
layer 2
MLAG Primary/Secondary roles
- MLAG peers negotiate a primary and secondary status within an MLAG domain
- Initially, switch with the lowest system MAC is elected MLAG primary
- Primary and Secondary status determine Layer 2 protocol operation
- Also generates an Mlag ____ to be used for L2 operation
System ID
MLAG Peer Link
Peer-link control traffic uses both UDP and TCP with port number ___
4432
MLAG Peer Link
Used to transport ___ and primary/secondary election (___)
keepalive messages, TCP
MLAG Peer Link
There is no ___ of MAC addresses from packets received on the peer link. MLAG peers rely on the MAC address sync for the same.
data plane learning
MLAG Peer Link
Used to tunnel ___ and to sync learned MAC addresses between MLAG peers
control traffic
MLAG Peer Link
There is no data plane learning of MAC addresses from packets received on the peer link. MLAG peers rely on the ___ for the same.
MAC address sync
MLAG Peer Link
Used to transport keepalive messages and ____
primary/secondary election
tcpdump filter for capturing MLAG peer-link control traffic:
'tcpdump int vlan 4094 filter port 4432' or the BASH equivalent, ____
bash tcpdump -nevi vlan4094 port 4432
Peer SVI MAC addresses are installed as ____ MAC addresses over peer-link when MLAG is active.
statically learned
Peer SVI MAC addresses are installed as statically learned MAC addresses over ___ when MLAG is active.
peer-link
MAC Address Synchronization
- For any new MAC address learned on an L2 port, the local switch will ___ the MAC address and ___ the peer through the MLAG control plane.
install, notify
MAC Address Synchronization
- When notified of a new MAC, the peer will install the MAC address in its address table.
- If the MAC was learned over an active-active MLAG ____, the peer will record the MAC as learned over the ____.
port-channel
MAC Address Synchronization
- When notified of a new MAC, the peer will install the MAC address in its address table.
- If the MAC was learned over an ____ MLAG port-channel, the peer will record the MAC as learned over the port-channel.
active-active
MAC Address Synchronization
- When notified of a new MAC, the peer will install the MAC address in its address table.
- For active-partial/orphan links, the peer will learn the MAC over the ____.
peer link
MAC Address Synchronization
- When notified of a new MAC, the peer will install the MAC address in its address table.
- For ____, the peer will learn the MAC over the peer link.
active-partial/orphan links
MAC Address Synchronization
Po100 is the peer link
Host 001c.7341.773d is attached to an ___
MLAG port-channel
MAC Address Synchronization
Po100 is the peer link
Host 001c.73ee.c3bb and host 001c.73ee.c52d are each attached to an ___
orphan link
MAC Address Synchronization
Po100 is the peer link
Host 001c.73ee.c52d is attached to Switch ___
Peer2
To see which mac was learned by a peer as opposed to by dataplane learning use command: ____
show mac address-table mlag-peer
The MLAG primary controls all ___ operations
STP
Only the global STP configurations on the MLAG current primary will be in effect for selecting STP type, ____ etc.
bridge priority
STP configuration should be ___ on the MLAG primary and secondary for seamless failover.
the same
Switches in MLAG use the MLAG System ID (MSI) as a common logical ___
bridge ID
All ___ will utilize the MLAG System ID (MSI) as the bridge ID
BPDUs
While the STP agent runs on the secondary, it ___ manage the protocol state machines and is often listed in documentation as ‘not running on the secondary’.
does not
STP control traffic is advertised from secondary to primary for processing via the peer-link on the ____
MLAG VLAN
BPDUs are transmitted ___ the primary and ____ by the secondary
from, forwarded
BPDUs are encapsulated in the ___ traffic
UDP peer link
If the logical bridge is the root then both peers will show ___
"This bridge is the root"
STP control traffic is advertised from ___ to primary for processing via the peer-link on the MLAG VLAN
secondary
Step 3 shows Core-1 performing _____ over the peer link to notify Core-2 with information about ____
MAC Address Synchronization, MAC "A"
Switch Edge-2 believes it is connected to a __ via a standard LAG
single switch
BUM traffic
In the diagram, MAC Syncs are sent from receiving switches to their peers because ___
There is no data plane learning of MAC addresses from packets received on the peer link.
BUM traffic
In the diagram, peer switches do not forward broadcasts on their port channel links because ___
the receiving switch's MLAG port is active
BUM traffic for single homed devices
In the diagram, switch SW-B1 broadcasts locally to the dual-attached ___ and to the upstream
Server B
BUM traffic for single homed devices
In the diagram, switch SW-B2 broadcasts locally only to the those hosts that are ___ on the peer switch
not active
BUM traffic for single homed devices
In the diagram, switch Core-2 does not forward the broadcast on its local MLAG links because ___
MLAG port (in Po201) is active on Core-1
BUM traffic for single homed devices
In the diagram, switch SW-C2 floods broadcast traffic out any __ links
partial-active or single-homed
MLAG provides ___ L2 topology
active-active
MLAG peer switches run ___ layer 3 control planes
separate
MLAG + VRRP
VRRP could be deployed to provide ___ redundancy
default gateway
MLAG + VRRP
Only one active ____ in the MLAG domain
default gateway
MLAG + VRRP
Only one active default gateway in the MLAG domain which results in ___ Layer 3 forwarding
active-standby
MLAG + VRRP
Traffic is ___ across the peer link under normal operation
forwarded
MLAG + VARP
VARP is used to achieve ___ default gateway forwarding
active-active
MLAG + VARP
Two VARP peers share a ___ VARP address
single
MLAG + VARP
A ____ consists of a Virtual IP address and MAC address (global)
VARP address
MLAG + VARP
Peer locally forwards traffic sent to the VARP MAC address locally, thus no need to forward traffic across the ____
peer link
MLAG + VARP
Each peer is responsible for ___ of local nodes
ARP
MLAG + VARP
GARP is sent periodically to refresh ____
MAC tables
MLAG + VARP
End nodes configured with the VARP IP as their ____
default gateway