Term
| what does the rip hello timer define? |
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Definition
| defines how often rip routes are advertised. |
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Term
| what is the default rip hello timer? |
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Definition
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Term
| commands to amend the rip hello timer. |
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Definition
routing process - "timers basic"
interface - "ip rip advertise" |
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Term
| desribe the rip invalid timer. |
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Definition
defines how long a device will wait before declaring a route invalid, after no updates have been received.
180 secs default.
Timer is reset every time an update is received. |
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Term
| describe the rip holddown timer. |
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Definition
defines how long a device will ignore inferior routes, after a route becomes invalid.
Default 180 secs
Timer begins when a route is marked as invalid. |
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Term
| describe the rip flush timer. |
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Definition
defines how long a device will wait before flushing a route that has not received an update.
Default 240 secs.
Timer is reset every time an update is received. |
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Term
| describe what happens when a rip router stops receiving updates for a route. |
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Definition
1. invalid and flush timers are reset when last update is received.
2. invalid timer expires and the route is marked as invalid.
3. Hold down timer begins.
4. route is flushed when flush timer expires.
5. device will accept inferior routes when hold down timer expires. |
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Term
| what extensions were added to ripv1 to create ripv2? |
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Definition
1. subnet masks
2. authentication
3. next-hop addresses carried with each route
4. external route tags
5. multicast route updates |
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Term
| how does ripv2 communicate i.e. address and port? |
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Definition
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Term
| how many routes can a rip update carry? |
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Definition
| 25 or 24 with authentication |
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Term
| what are the 2 rip message types? |
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Definition
request - command field set to 1
response - command field set to 2 |
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Term
| list the rip compatibility switches and commands to implement. |
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Definition
these enable compatibility between v1 and v2
1. RIP-1 - only V1 messages transmitted - ip rip send ver 1
2. RIP-1 Compatibility - V2 messages are broadcast - ip rip v2-broadcast
3. RIP-2 - V2 updates are multicast - default
4. None - no updates sent - passive-interface |
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Term
| describe the rip receive control switch. |
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Definition
1. RIP-1 only - ip rip receive version
2. RIP-2 only - ip rip receive version
3. Both - ip rip receive version
4. None - use ACL to filter UDP 520 |
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Term
| an older switch may use classful lookups by default, what command will enable classless lookups. |
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Definition
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Term
| what is the defining characteristic of a classless routing protocol? |
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Definition
| the capability to carry subnet mask info in a routing update. |
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Term
| the advertisement of subnet mask info enables the use of all zeros subnet, but what additional command is required to enable this? |
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Definition
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Term
| what challenges is rip authentication designed to overcome? |
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Definition
| invalid updates from an attacker or malfunctioning device. |
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Term
| what type of rip messages will a router send/receive by default? |
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Definition
send - V1
receive - V1 & V2 |
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Term
| explain why we need to turn off auto-summarisation in networks with discontiguous subnets. |
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Definition
| Only classful summary routes can be advertised into another classful network when auto summary is enabled |
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Term
| how does the rip process choose an authentication key chain when multiple have been configured? |
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Definition
| Key numbers are examined lowest to highest, and the first valid key is used. |
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Term
| what function does the "bfd all-interfaces" feature provide? |
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Definition
| BFD is enabled on all interfaces. Provides failure detection and faster failover. "BFD" command is used in anmed mode >15.0 |
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Term
| how can a conditional default route be generated on a device? |
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Definition
Specify conditional route in standard acl.
Reference acl in route-map.
reference route-map in default-information originate command. |
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Term
| what function does the "flash-update-threshold" feature provide? |
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Definition
| if a flash update needs to be sent for a failing route, it will be suppressed if the regular update is due in LE the value specified by the flash-update-threshold. |
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Term
| what function does the "input-queue" feature provide? |
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Definition
defines the size of the RIP input queue in octets.
Default is 50, range 0-1024.
can be useful on a low end device that is receiving routes from a high end device. |
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Term
| what function does the "ip rip initial-delay" feature provide? |
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Definition
| delays MD5 authentication for the defined time after a link is established. Some non-cisco devices get a sad-on if the first MD5 packet received is greater than 0. |
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Term
| what function does the "ip rip triggered" feature provide? |
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Definition
| only sends triggered updates, useful for on-demand circuits. |
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Term
| what function does the "neighbor" feature provide? |
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Definition
| enables unicast updates. BFD can also be specified. |
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Term
| what function does the "output-delay" feature provide? |
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Definition
Specifies delay between packets in multiple packet updates.
Useful when a high end device is sending to a low end device quickly. May prevent routing updates from being dropped. |
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Term
| what function does the "show ip rip neighbors" feature provide? |
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Definition
| displays RIP neighbors for which BFD sessions are created. |
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Term
| what function does the "throttle" feature provide? |
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Definition
will throttle responses to requests to 1 per minute.
Can only be used with output-delay.
May prevent the loss of incoming updates when there are many routers. |
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Term
| what function does the "validte-update-source" feature provide? |
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Definition
| ensures that the source IP address of incoming routing updates is on the same IP network as one of the addresses defined for the receiving interface. |
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Term
| what 6 pieces of info are carried for every route in a RIPv2 message? |
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Definition
afi
tag
ip address
mask
next hop
metric |
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Term
| how will a ripv2 passive interface function? |
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Definition
| the interface will listen to updates but not send them. |
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Term
| what rip authentication methods must have an identical key-id |
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Definition
| MD5 only, as the key-id is not carried in a message using clear text authentication. |
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