A Few Questions
mattsthe2
Member Posts: 304
in CCNA & CCENT
Morning Guys,
1) How would I find out which switch is the Root Bridge when....
+ only one console connection is available to a single switch.(lets say the switch you do have a console connection to isnt the Root)
+ Telnet is not available to other switches
+ and cdp info is not available also.
2) which static route statment is preferred.
say you were asked to create a static route to 192.168.10.0
which option would you pick if you had the following to choose from:
A) ip route 192.168.10.0 serial0
ip route 192.168.10.0 192.168.5.1
1) How would I find out which switch is the Root Bridge when....
+ only one console connection is available to a single switch.(lets say the switch you do have a console connection to isnt the Root)
+ Telnet is not available to other switches
+ and cdp info is not available also.
2) which static route statment is preferred.
say you were asked to create a static route to 192.168.10.0
which option would you pick if you had the following to choose from:
A) ip route 192.168.10.0 serial0
ip route 192.168.10.0 192.168.5.1 Comments
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networker050184
Mod Posts: 11,962 Mod
1- show spanning-tree
2- you should always use the next hop on multi access networks, using the interface will have administrative distance of 0 and to a next hop would be 1An expert is a man who has made all the mistakes which can be made. -
mattsthe2
Member Posts: 304
networker050184 wrote:1- show spanning-tree
2- you should always use the next hop on multi access networks, using the interface will have administrative distance of 0 and to a next hop would be 1
1- that gives me the mac not the ip address or the switch name?
You just triggered something in my brain - an arp lookup. But i cant find a match for the mac address?
2- thanks. -
r_durant
Member Posts: 486 ■■■□□□□□□□
When you do the show spanning-tree, it should give you which port the root bridge is coming in on...or just look at the mac-address from the show spanning-tree and then look up the port which the show mac-address command
Then do a show cdp neighbor detail and all the connected devices should be listed and the ports their connected on...CCNA (Expired...), MCSE, CWNA, BSc Computer Science
Working on renewing CCNA! -
mattsthe2
Member Posts: 304
r_durant wrote:When you do the show spanning-tree, it should give you which port the root bridge is coming in on...or just look at the mac-address from the show spanning-tree and then look up the port which the show mac-address command
Then do a show cdp neighbor detail and all the connected devices should be listed and the ports their connected on...
The sh spanning-tree does indeed give me the mac towards the root port . But i couldnt find the mac in the mac-address table.
Also from my oringal post i said that cdp commands are not available to use at my disposal.
Guess Again.
??? -
Mikdilly
Member Posts: 309
2- you should always use the next hop on multi access networks, using the interface will have administrative distance of 0 and to a next hop would be 1
If next hop has a higher admin distance, why would you use it instead of the interface? -
networker050184
Mod Posts: 11,962 Mod
If you have a mutli access network such as ethernet you would want to specify which router will recieve the packet as there may be more than one out the interface. I always use the next hop just to be safe!An expert is a man who has made all the mistakes which can be made.
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mattsthe2
Member Posts: 304
I guess a
sh arp would help to at least match the mac to an ip address pointing towards the Root.
If its not in the arp table the sh spanning-tree wont be much help other than give me the mac. -
Plazma
Member Posts: 503
you can do show arp to map the ip to the MAC or you can do show cdp neighbors detail
thatll tell you everythingCCIE - COMPLETED! -
mikearama
Member Posts: 749
Well, if this is a test, Matt, I'm stuck. You have an answer?
On a L2 Cat 3750, I don't think it's possible to find the IP, given your limitations. For example:
SRV-SW2#sh spanning-tree
VLAN0009
Spanning tree enabled protocol rstp
Root ID Priority 9
Address 0011.207a.c2c0
Cost 3
Port 696 (Port-channel11)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---- ---
Gi2/0/28 Desg FWD 19 128.80 P2p Peer(STP)
Po11 Root FWD 3 128.696 P2p
Po12 Altn BLK 3 128.704 P2p
SRV-SW2#sh mac-address-table address 0011.207a.c2c0
Mac Address Table
Vlan Mac Address Type Ports
----
12 0011.207a.c2c0 DYNAMIC Po12
Total Mac Addresses for this criterion: 1
SRV-SW2#sh ip arp 0011.207a.c2c0
SRV-SW2#sh ip arp port-channel 12
SRV-SW2#
No telnet to anything L3, and no CDP... that makes it tough.There are only 10 kinds of people... those who understand binary, and those that don't.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project. -
r_durant
Member Posts: 486 ■■■□□□□□□□
Matt...
What is the source of your question? If you care to divulge...
CCNA (Expired...), MCSE, CWNA, BSc Computer Science
Working on renewing CCNA! -
mattsthe2
Member Posts: 304
on a more important note i now have three stars below my name on techexams...this is quite a momentous occasion.
These means one of two things:
1) im a geek that spends way to much time reading up on CCNA issues.
2) see 1)
