Things to Remember Flashcards
Which OSPF network types do not require a DR/BDR?
- Point-to-point
- Point-to-multipoint
EIGRP Summarization Commands
- Classic mode
- Named mode
- Route to NULL0 installed?
- on the interface “ip summary-address eigrp 4 172.16.0.0 255.255.0.0
- under AF-Interface “summary-address 172.16.0.0/16
- Yes
Regarding BFD:
- what does BFD stand for?
- what does it require in order to operate?
- how does it work?
- which 2 places is it enabled?
- Bidirectional Forwarding Detection
- CEF
- Sends small fixed-length keepalive packets detecting failures in less than a second
- it is enabled on the interfaces and under the routing protocol
OSPF Summarization Commands:
- for ABR
- NULL0 route auto-installed?
- for ASBR
- NULL0 route auto-installed?
- area 0 range 172.16.0.0 255.255.0.0
- yes
- summary-address 172.16.0.0 255.255.0.0
- yes with metric of 254
BGP Summarization Commands:
- Route to NULL0 auto-installed?
- aggregate-address 172.16.0.0 255.255.0.0 summary-only as-set
- yes
Regarding uRPF:
- what does uRPF stand for
- what does it do
- what does it require
- what modes does it operate in
- Unicast Reverse Path Forwarding
- it compares the source address of a packet and checks to see if the packet came in the same interface the router would use to get to the source
- CEF
- Strict, Loose, and VRF
In OSPF, for each of the following stub area types list 1) which LSA type is not allowed by any stub network types; 2) which stub areas allow ASBRs; and 3) what is not allowed by the ‘Totally’ stub types?
- None of the Stub network types allow Type 5 LSAs so they all need a default route (the NSSA is the only type that needs it manually installed)
- ASBRs are only allowed in NSSA and Totally NSSA
- Both ‘Totally’ types don’t allow LSAs 3 and 5
What protocol numbers are used by the following:
- OSPF
- EIGRP
- BGP
- IP 89
- IP 88
- TCP 179
What multicast addresses do the following use:
- EIGRP
- OSPF
- EIGRP - 224.0.0.10
- OSPF - 224.0.0.5 and 224.0.0.6
In EIGRP, which show command would display authentication parameters such as authentication mode and keychain being used?
“show ip eigrp interfaces detail”
What is the source and destination of:
- EIGRPv6 Hello Messages?
- EIGRPv6 Update Messages?
- Hello’s are sourced from Link Local address FE80::/10 and destined for FF02::A
- Update messages are sourced and destined for link local addresses
In OSPF, which state do routers send LSRs and LSUs to each other?
Loading
In OSPF, which area types do not permit ASBRs?
- Stub
- Totally Stubby
In OSPF, what show command displays the timers configured on an interface?
“show ip ospf interface”
In OSPF, can neighbors with different network types form a full neighborship?
Yes, as long as the timers match
In OSPF, what do the following option bits mean:
- E-bit
- DC-bit
- N-bit
- MC-bit
- V6-bit
- R-bit
- E-bit - capable of processing external LSAs
- DC-bit - capable of suppressing future Hellos
- N-bit - supports Type 7 LSAs
- MC-bit - supports Multicast
- V6-bit - router is participating in IPV6 routing
- R-bit - router actively participates in forwarding traffic
In OSPFv3, which ‘show’ command will display whether the area is participating in authentication?
“show ospfv3”
In OSPFv3, which ‘show’ command will display the reference bandwidth?
“show ipv6 ospf”
In OSPFv3, which command will display whether the local router has injected a default route?
“show ospfv3”
In EIGRP Named Mode, what command enables EIGRP on an interface?
“network” command
In EIGRP, by default, what is the maximum amount of bandwidth that EIGRP is allowed to use on a link?
50%
In classic EIGRP, where do you modify the Hello and Hold timers/
On the interface.
In EIGRPv6, what show command can you use to determine if a remote router is a stub router?
“show ipv6 eigrp neighbors detail”
In OSPFv3, which 2 show commands display whether a router is an ABR?
- “show ipv6 ospf”
- “show ipv6 protocols”
In BGP, which ‘show’ command can verify the incoming and outgoing TTL values?
“show bgp ipv4 unicast neighbors”
When using a route-map for redistribution, there are 3 conditions that can be used to match prefixes. What are they?
- Route type
- Outbound interface
- Prefix List
In EIGRP for IPV4, which 2 ‘show’ commands can you use to determine the value of K-6?
- “show ip protocols”
- “show eigrp protocols”
In OSPF, how is the cost of a link calculated?
Reference bandwidth of 100 Mbps / Interface bandwidth
The assumption was that reference bandwidth would always be greater than interface bandwidth. Today it’s not.
What are the 4 well-known communities and what do they mean?
- Internet - advertise the prefix to all BGP neighbors
- No-advertise - don’t advertise the prefix to any BGP neighbors
- No-export - don’t advertise the prefix to any eBGP neighbors (other ASs)
- Local-as - don’t advertise the prefix outside the confederation
When redistributing from BGP into OSPF what kind of routes will be redistributed?
Only eBGP routes.
Which OSPF network types set the Hello timer to 30 sec?
- Non-broadcast
- Point-to-multipoint
In OSPFv3 which instance numbers are valid for IPv6 and which are valid for IPV4?
- IPV6 - 0 to 31
- IPV4 - 64 to 95
In LFA FRR, What are the 8 tie-breakers?
- 0 post-convergence
- 10 primary-path
- 20 interface-disjoint
- 30 lowest-metric
- 40 linecard-disjoint
- 50 broadcast-interface-disjoint
- 256 load-sharing
What authentication types do each of the following routing protocols support?
- EIGRP
- OSPF
- OSPFv3
- BGP
- EIGRP
- MD5
- SHA-2 (named mode)
- OSPF
- Plain text
- MD5
- HMAC SHA
- OSPFv3
- IPsec with AH or ESP
- BGP
- MD5
What is the default reference bandwidth for OSPF
100 Mbps
What is EIGRPs retry limit when trying to communicate with a router that is not responding?
The retry limit is 16
In OSPFv3, if instance numbers are not provided what values do they default to?
- IPv6 defaults to 0
- IPv4 defaults to 64
