Flash Cards - OSPFv2

OSPF Packet Types (HD_RUA):

Type 1 - Hello / Type 2 - Database Descriptor / Type 3 - Link-State Request / Type 4 - Link-State Update / Type 5 - Link-State Acknowledgment.

OSPF uses protocol 89 - LSA Aging time 30 minutes / Can be changed: timers pacing lsa-group <Time in Minutes>

When you do a show ip ospf database network - The routing bit set means its a good route and in the RIB.

To inject a default route into OSPF, you need to have one configured already. Or you can use the command:

#Router ospf 1
#default-information originate always

If you are peering with non-cisco routers and having trouble. LLS is th ability to exchange vendor specific data within OSPF packets.

#Router ospf 1
#no capability lls (Link-local Signaling (LLS) support)

OR

intf#ip ospf lls disable
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P2P Sub-interfaces - Inverse ARP is disabled by default.

To change the default metric:

Router ospf 1
default-metric <#>

The default redistribution metric is <20>

#ip ospf flood-reduction (Sets the DoNotAge bit)

Hide the MPLS network when someone uses a traceroute:

#no mpls propogate-ttl

Router ospf 1
#max-metric router-lsa <on-startup | time | wait-for-bgp>
#redistribute maximum-prefix <#> <Threshold | warning-only>

OSPF Filtering

Type 1-2 LSA - On ABR

#area 1 range 10.1.1.0 255.255.255.0 <default is advertise> <not-advertise | cost>

#distribute-list 1 <route-map> in

Type 3 LSA - On ABR

#area 2 filter-list prefix <name> in

Type 5 - 7 - ASBR

#summary-address 10.1.1.1 255.255.255.0 <not-advertise>

#distribute-list 1 out

IPv6 Tunneling

~ P2P IPv6 Tunnels ~


Manual

Tunnel source  / destination should be an IPv4 address.

Tunnel IP should be an IPv6 address.

Tunnel mode IPv6IP

Manual GRE

Tunnel source  / destination should be an IPv6 address.

Tunnel IP should be an IPv6 address.

Tunnel Mode GRE IPv6


~ P2MultiPoint IPv6 Tunnels ~


Automatic 6-4


Used for IPv6 Source / Destination over an IPv4 Network.

Sites use 2002::/16 prefix -- Format 2002:border_router_ipv4_address::/48

Tunnel Source IPv4 address / No tunnel destination required

Tunnel IP address is IPv6 address

Tunnel mode IPv6IP 6to4

ipv6 route 2002::/16 tunnel 0

ISATAP (Intra-site automatic tunnel addressing protocol) 


You can use any IPv6 address that you desire unlike auto 6-4. Used for transporting IPv6 within a site, not between.

Interface ID is created using EUI-64 address which is embeeded in last 32 bit of the IPv6 address. e.g. mac_add-FFFE-mac_address

Tunnel IPv6 2001:1234::/64 EUI-64

Tunnel mode IPv6IP ISATAP

Need to add "no ipv6 ND ra-suppress" / "no ipv6 nd suppress-ra

IPv6 OSPF v3 LSA Types

Link State Type field is 16 bits rather than 8 with IPv4.

 

 OSPFv3 removes the prefix advertisement function from router and network LSAs and puts it in the new Intra-Area Prefix LSA and Link LSA

The Router LSA - OSPFv3

This only describes the originating router and it's links to its neighbors. Prefix information is carried in the intra-area prefix LSA

The Network LSA - OSPFv3

Functionally it is identical to the OSPFv2 Network (Type 2 LSA)

The Inter-Area Prefix LSA - OSPFv3

Functionally it is identical to the OSPFv2 Summary (Type 3 LSA)

The Inter-Area Router - OSPFv3

Functionally it is identical to the OSPFv2 ASBR Summary (Type 4 LSA)

 The AS-External LSA - OSPFv3

Functionally it is identical to the OSPFv2 AS External (Type 5 LSA) except for:

The Link LSA - OSPFv3

The link LSA is used for communicating information that is significant only to two directly connected neighbors. A separate link LSA is originated on each if a routers attached links belonging to an OSPFv3 domain.

The Intra-Area Prefix LSA - OSPFv3

MPLS - LDP

MPLS Label Protocol - LDP

MPLS ldp router-id - Best to set it as the IP must be reachable as it is used in the transport addresss in the LDP discovery hello messages.

#mpls label protocol ldp

#mpls label router-id loopback0 <force>

#mpls label range 100 200

Once you enable #mpls ip on an interface, the LSR will attempt to discover neighbors using hello messages that are sourced from UDP 646 224.0.0.2 every 5 seconds (Hold time 15 sec)

2.2.2.2:0 The zero is a 2 Byte value and indicates that its platform wide and anything other than zero indicates that its per-interface.

#show mpls ldp neighbor

There are (2) types of neighbor discovery: i. Basic ii. Extended
Basic- Sends a discover message out every interface in which mpls ip is enabled.
Extended- Sends discover messages to non-directly connected LDP neighbors.


#show mpls ldp discovery all


#show mpls ldp discovery detail


#show mpls ldp parameters


#mpls ldp discovery hello holdtime 45
#mpls ldp discovery hello interval 15
#mpls ldp holdtime 90 <This will change the keep-alive time auto-magically>

This shows the routers <LIB>
#show mpls ldp binding <6.6.6.6>

This shows the <LFIB>
#show mpls forwarding-table <6.6.6.6>


This shows the <FIB>
#show ip cef 6.6.6.6

To configure a router as a PHP:

#mpls ldp explicit-null

#intf fa0/0 - mpls ip

 

To stop advertising labels all together:

#no mpls ldp advertise-labels

QoS

A source is on v100 generating 10 UDP PPS, the packet size is 1024 Bytes and is destined for v20 of switch 1 UDP port 5011.

Limit the traffic to 8000b/s, excess should be dropped and set the DSCP value to 18.

HEIRARCHIAL POLICY MAP-

Level 1 affects the SVI traffic and Level 2 affects interface level traffic.

mls qos
class-map cm-interfaces (Child)
match input-interface fastethernet 0/10
!
class-map udp-5011 (Child)
match access-group 101
!
policy-map pm-interfaces (Child)
class cm-interfaces
police 8000 8000 exceed-action drop
!
polcy-map pm-vlan100 (Parent)
class udp-5011
set dscp af21
service-policy pm-interfaces
!
interface fastethernet 0/10
mls qos vlan-based
!
interface vlan100
service-policy input pm-vlan100
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