IPv6 Redistribute with include-connected

For IPv6 whether or not connected links are included in redistribution is up to you at the time of configuration.


http://blog.ine.com/2008/01/15/understanding-how-redistribution-works-in-ipv6/

Differences between OSPFv3 and OSPFv2

1. Configured using interface command
2. Advertising multiple networks on an interface
3. OSPFv3 RID must be set
4. Flooding scope (link-local, area, AS)
5. Multiple instance per link
6. Source packets from link-local address (except virtual link)
7. Authentication using AH / ESP
8. New LSA Types:

1. Intra-Area Prefix LSA (Type 9)
2. Link LSA (Type 8)
1. Router LSA can be split across multiple LSAs; Link State ID in LSA header is a fragment ID

http://academy.itu.int/moodle/pluginfile.php/38185/mod_resource/content/1/4%20-%20OSPFv3.pdf

IPv6 and IPv4 QoS Differences

Differences:

• There is no equivalent for match ip rtp in IPv6
• IPv6 access lists cannot be numbered

Differences between EIGRP for IPv4 and IPv6

1. Configured on interface
2. Must no shut the routing process
3. 32-bit router ID
4. Passive interface
5. Route filtering: only distribute-list prefix-list
6. Automatic summarisation
7. Cisco IOS support: 12.4(6)T
8. No auto-summary, as there is no classful concept anymore

CCIE Routing and Switching Certification Guide (4th edition)

IPv6 Neighbour Discovery Lifetime

The value indicates the usefulness of the router as a default router on this interface.Setting the value to 0 indicates that the router should not be considered a default router on this interface.

ipv6 nd ra lifetime superseded the old ipv6 nd ra-lifetime interface command.

Best Practice Recommendations for the Catalyst 6500 Series Switch

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/best/practices/recommendations.html

Etherchannel Mode On and Spanning Tree Loop

A common issue during EtherChannel configuration is that the interfaces go into err-disable mode. This can be seen when Etherchannel is switched to the ON mode in one switch, and the other switch is not configured immediately. If left in this state for a minute or so, STP on the switch where EtherChannel is enabled thinks there is a loop. This causes the channeling ports to be put in err-disable state.


n order to resolve the issue, set the channel mode to desirable on both sides of the connection, and then re-enable the interfaces.


http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a0080094647.shtml

When RSTP flushes CAM table?

1. When transitioning from discarding to forwarding
2. Upon receiving a topology change notification (TCN)

BPDU Guard

• Prevents a switch to be added to a port by mistake
• If any BPDU is received port will be put in err-disable
• Used with portfast ports
• Can't be used with root guard
• Blocks the whole port

Switch(config)# spanning-tree portfast bpduguard default

Switch(config-if)# spanning-tree bpdugard enable

MST Configuration

For MST to work between two switches the following has to be the same:

1. Name
2. Revision Number
3. Instance to VLAN Mapping

Switch(config)# spanning-tree mode mst

Switch(config)# spanning-tree mst configuration

Switch(config-mst)# name <instance-name>

Switch(config-mst)# revision <revision-number>

Switch(config-mst)# instance <instance-id> vlan <vlan-list>

Switch(config)# spanning-tree mst <instance-id> root [primary | secondary] diameter <diameter>

Switch(config)# spanning-tree mst <instance-id> priority <bridge-priority>

Switch(config-if)# spanning-tree mst <instance-id> cost <cost>

Switch(config-if)# spanning-tree mst <instance-id> port-priority <port-priority>

Switch(config)# spanning-tree mst <instance-id> mst hello-time <seconds>

Switch(config)# spanning-tree mst <instance-id> mst forward-time <seconds>

Switch(config)# spanning-tree mst <instance-id> mst max-age <seconds>

Difference between VTP versions

VTP version 1:

• Supports normal VLAN numbers (1-1001)
• Supports pruning of unused VLANs (no longer sends broadcasts and unknown unicasts
• supports cleartext and MD5 digest password

VTP version 2:

• Forwards the VTP messages without checking the version number or domain in transparent mode
• Supports Token Ring
• Performs consistency check on the VTP / VLAN parameters (from CLI or SNMP)
• Pass on Unrecognised TLVs

VTP version 3:

• Supports extended VLAN numbers (1-4095)
• Transfer information regarding Private VLAN structure
• Support for databases other than VLAN (for example MST)
• Protection from unintended database overrides during insertion of new switches
• Hidden password protection

- CCNP SWITCH 642-813 Official Certification Guide

- http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/solution_guide_c78_508010.html

Loop Guard

When BPDUs go missing, port is moved to loop inconsistent and kept in nondesignated role

• It only operates on interfaces that are considered point-to-point by the spanning tree.
• It can't be used with root guard
• It operates per VLAN
• It recovers automatically

EIGRP Interface Load (K2)

EIGRP routing updates are triggered only by a change in network topology (interface up/down event, IP addressing change or configured bandwidth/delay change) and not by change in interface load or reliability. The load/reliability numbers are thus a snapshot taken at the moment of the topology change and should be ignored.

http://blog.ioshints.info/2009/06/eigrp-load-and-reliability-metrics.html

EIGRP routing over DMVPN (mGRE)

On Hub:

• Disable as-member split-horizon
• Disable as-member next-hop-self

EIGRP traffic-share min

when you use the traffic-share command with the keyword min, the traffic is sent only across the minimum-cost path, even when there are multiple paths in the routing table. This is identical to the forwarding behaviour without use of the variance command. However, if you use the traffic-share min command and the variance command, even though traffic is sent over the minimum-cost path only, all feasible routes get installed into the routing table, which decreases convergence times.

1. traffic-share balanced (default):
1. Variance=1 (default):
1. Traffic will be sent to successor(s) only (equal cost load balancing).
2. Feasible successors are kept in EIGRP topology table.
3. Feasible successors are not kept in the routing table.
2. Variance=2+:
1. Traffic will be sent to successor(s) and feasible successors(s).
2. Traffic will be sent inversely proportional to their metrics.
3. All successor(s) and feasible successor(s) are kept in the routing table.
2. traffic-share min across-interfaces:
1. Variance=1 (default):
1. same as (1.1)
2. Variance=2+:
1. Traffic will be sent to successor(s) only (equal cost load balancing).
2. Feasible successors are kept in the routing table.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009437d.shtml

http://blog.ine.com/2009/05/01/understanding-unequal-cost-load-balancing/