EIGRP Flashcards
Which type of authentication supports EIGRP?
Only supports MD5
What are the requirements to became EIGRP neighbor?
- Must be able to send/receive IP packets
- The primary IP address of the interface must be in the same subnet
- AS number must be the same
- Connected interface must not be passive
- Authentication must pass
- K-values used must match
Which information omits the “show ip eigrp interfaces” command?
It omits the passive interfaces
Which protocol shows the passive interfaces in EIGRP?
Show ip protocol
How can you manually change the EIGRP hello and hold intervals?
Ip hello-interval eigrp
Ip hold-time eigrp
Interval = seconds
What is the default time for hello and hold intervals in EIGRP?
LAN > hello: 5sec ; hold: 15sec
WAN > hello: 60sec ; hold: 180sec
Which command is used to see in EIGRP the K-values?
Show ip protocols
How can you change the K-values?
Metric weights 0 1 0 1 0 0
Where the 1st value is the tos that is always 0
How long does the router wait to act when no hello packets are received?
3x hello-interval. By default 15 seconda
What is the EIGRP multicast address in IPv4 to send hello?
224.0.0.10
Which device is affected by the change of the hello and hold timers?
Hello timer > local device
Hold timer > the neighbors
Which commands can you use to verify the hello and dead intervals in EIGRP?
- show ip eigrp interface detail
* show ip eigrp neighbors (no muestra el tiempo exacto sino un contador)
What are the uses of DUAL?
- Determine the best loop-free path
- Determine the backup loop-free path
- Provide fast convergence
What is the IP protocol number of EIGRP?
88
What type of protocol is EIGRP?
Distance vector
What are the 3 steps in EIGRP to provide network convergence?
- Neighbor relationship
- Topology exchange information
- DUAL to populate the routing table
In EIGRP, what are the purposes of the hello packets?
- Discover new neighbors
2. To maintain the neighborship
What is the importance of enable the authentication in a routing protocol?
This helps to prevent a Denial of Service (DoS) attack
If in EIGRP you have the following commands:
R1 > “key chain CCNP”
R2 > “key chain Cisco”
Do you think that this could work? And why?
Yes, because the name or string only have a locally importance
In EIGRP, how would you configure the authentication?
Key chain "string" Key 1 Key-string "string" Interface fastEthernet 0/1 Ip authentication mode eigrp 1 md5 Ip authentication key-chain eigrp "key-chain-string"
If in EIGRP you have multiple active/valid keys at the same time, which key would be used to generate the MD5 digest to send EIGRP packets?
The key with the lowest key number value
In EIGRP how can you check the key chain configuration?
- “show key chain “
* “debug eigrp packet”
Can you configure key chain to use time-based logic?
Yes
In EIGRP if you wanted to use different keys during different time periods what would you need to do on router so this configuration could work?
The clocks must be set to use the same time, using and NTP or manually through the “clock set” command
Which commands you have to use to configure the key chain to use time-based logic?
- accept-lifetime…
- send-lifetime…
What do you need to do to use different keys during different time periods?
The clocks must be set to use the same time. You can configure it manually or using a NTP server (preferred).
Which command you have to use to update the router clock manually?
“Clock set” command