Why would a system administrator use the tag-switching atm maxhopsgloabal configuration command?
A.
In large ATM-MPLS networks, the LFIB can become too large. Because of this, it is necessary to limit the maximum diameter of the MPLS network.
B.
TDP relies exclusively on hop-count carried in the TDP request and replay packets to detect loops during the downstream-on-demand label allocation.
C.
LDP does not support using Router ID to detect routing information in ATM networks during the downstream-on demand label allocation process.
D.
Because end-to-end delay can cause problems with some voice applications, it is necessary to limit the maximum diameter of the MPLS network.
Explanation:
1) According to the "Implementing Cisco MPLS" Student Guide (Text Part Number: 97-1153-01) Volume 1, version 1.0, page 6-11. tag-switching atm maxhops: Router ID can be used in LDP to detect routing information loops in ATM networks during downstream-on-demand label allocation process. TDP does not support this option and relies exclusively on hop-count carried in the TDP requests and reply packets to detect loop during the downstream-on-demand label allocation.
2) According to cisco: see the following website
http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_command_reference_chapter09186a00 tag-switchingatm maxhops To limit the maximum hop counts to a value you have specified, use the tag- switching
atm maxhops global configuration command. Use the no form of this command to ignore the hop count.
tag-switchingatm maxhops [number]
notag-switching atm maxhops
Syntax Description
number(Optional) Maximum hop count.Defaults
The default is 254.
Command Modes
Global configuration
Command History
Release Modification 11.1 CTThis command was introduced.Usage Guidelines When an ATM TSR receives a BIND REQUEST, it does not send a BIND back if the value in the request is equal to the maxhops value. Instead, the ATM TSR or TSR returns an error that specifies that the hop count has been reached. When an ATM-TSR initiates a request for a tag binding, it includes a parameter specifying the maximum number of hops that the request should travel before reaching the edge of the ATM Tag Switching region. This is used to prevent forwarding loops in setting up tag paths across the ATM region.
Examples
The following example sets the hop count limit to 2:
tag-switching atm maxhops 2
Related Commands
Command Description show tag-switching atm-tdp bindingsDisplays the requested entries from the ATM TDP tag binding database.