10-02-2013 12:22 AM - edited 03-04-2019 09:12 PM
Hey guys
I'm dong INE labs and bumped into a wierd issue that .
I've configured the dmz-link bandwidtha nd the extended communities to be sent , I'm receiving the bandwidth in the BGP routes , however the routing table doesnt change the traffic share according to the available link bandwidth .
following is my configuration :
Rack1R6(config)#do sh run | sec bgp
router bgp 100
no synchronization
bgp log-neighbor-changes
bgp dmzlink-bw
network 155.1.146.0 mask 255.255.255.0
aggregate-address 155.1.0.0 255.255.0.0 summary-only
neighbor 54.1.1.254 remote-as 54
neighbor 54.1.1.254 dmzlink-bw
neighbor 155.1.67.7 remote-as 300
neighbor 155.1.146.1 remote-as 100
neighbor 155.1.146.1 send-community both
no auto-summary
Rack1R6(config)#
Rack1R6(config)#do sh ip bgp neigh 155.1.146.1 adver
BGP table version is 35, local router ID is 150.1.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 28.119.16.0/24 54.1.1.254 0 54 i
*> 28.119.17.0/24 54.1.1.254 0 54 i
*> 112.0.0.0 54.1.1.254 0 0 54 50 60 i
*> 113.0.0.0 54.1.1.254 0 0 54 50 60 i
*> 114.0.0.0 54.1.1.254 0 0 54 i
*> 115.0.0.0 54.1.1.254 0 0 54 i
*> 116.0.0.0 54.1.1.254 0 0 54 i
*> 117.0.0.0 54.1.1.254 0 0 54 i
*> 118.0.0.0 54.1.1.254 0 0 54 i
*> 119.0.0.0 54.1.1.254 0 0 54 i
r> 155.1.0.0 0.0.0.0 32768 i
Rack1R6(config)#do sh ip bgp
BGP table version is 35, local router ID is 150.1.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i28.119.16.0/24 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 54 i
* i28.119.17.0/24 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 54 i
* i112.0.0.0 204.12.1.254 0 100 0 54 50 60 i
*> 54.1.1.254 0 0 54 50 60 i
* i113.0.0.0 204.12.1.254 0 100 0 54 50 60 i
*> 54.1.1.254 0 0 54 50 60 i
* i114.0.0.0 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 0 54 i
* i115.0.0.0 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 0 54 i
* i116.0.0.0 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 0 54 i
* i117.0.0.0 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 0 54 i
* i118.0.0.0 204.12.1.254 0 100 0 54 i
Network Next Hop Metric LocPrf Weight Path
*> 54.1.1.254 0 0 54 i
* i119.0.0.0 204.12.1.254 0 100 0 54 i
*> 54.1.1.254 0 0 54 i
r i155.1.0.0 155.1.146.4 0 100 0 i
r> 0.0.0.0 32768 i
s> 155.1.146.0/24 0.0.0.0 0 32768 i
*>i205.90.31.0 155.1.13.3 0 100 0 200 254 ?
* 155.1.67.7 0 300 200 254 ?
*>i220.20.3.0 155.1.13.3 0 100 0 200 254 ?
* 155.1.67.7 0 300 200 254 ?
*>i222.22.2.0 155.1.13.3 0 100 0 200 254 ?
* 155.1.67.7 0 300 200 254 ?
Rack1R6(config)#
######################## now R4 configuration
Rack1R4(config)#do sh run | sec bgp
router bgp 100
no synchronization
bgp log-neighbor-changes
bgp dmzlink-bw
network 155.1.146.0 mask 255.255.255.0
aggregate-address 155.1.0.0 255.255.0.0 summary-only
neighbor 155.1.45.5 remote-as 200
neighbor 155.1.45.5 route-map MATCH-54 out
neighbor 155.1.146.1 remote-as 100
neighbor 155.1.146.1 send-community both
neighbor 204.12.1.254 remote-as 54
neighbor 204.12.1.254 dmzlink-bw
no auto-summary
Rack1R4(config)#
Rack1R4(config)#do sh ip bgp summ
BGP router identifier 150.1.4.4, local AS number 100
BGP table version is 18, main routing table version 18
15 network entries using 1980 bytes of memory
18 path entries using 936 bytes of memory
9/7 BGP path/bestpath attribute entries using 1512 bytes of memory
3 BGP AS-PATH entries using 72 bytes of memory
1 BGP community entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
Bitfield cache entries: current 3 (at peak 5) using 96 bytes of memory
BGP using 4620 total bytes of memory
BGP activity 102/87 prefixes, 243/225 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
155.1.45.5 4 200 8615 8640 18 0 0 07:38:02 3
155.1.146.1 4 100 8761 8668 18 0 0 00:14:34 3
204.12.1.254 4 54 8724 8595 18 0 0 07:38:02 10
Rack1R4(config)#do sh ip bgp
BGP table version is 18, local router ID is 150.1.4.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 28.119.16.0/24 204.12.1.254 0 0 54 i
*> 28.119.17.0/24 204.12.1.254 0 0 54 i
*> 112.0.0.0 204.12.1.254 0 54 50 60 i
*> 113.0.0.0 204.12.1.254 0 54 50 60 i
*> 114.0.0.0 204.12.1.254 0 54 i
*> 115.0.0.0 204.12.1.254 0 54 i
*> 116.0.0.0 204.12.1.254 0 54 i
*> 117.0.0.0 204.12.1.254 0 54 i
*> 118.0.0.0 204.12.1.254 0 54 i
*> 119.0.0.0 204.12.1.254 0 54 i
*> 155.1.0.0 0.0.0.0 32768 i
s> 155.1.146.0/24 0.0.0.0 0 32768 i
* i205.90.31.0 155.1.13.3 0 100 0 200 254 ?
*> 155.1.45.5 0 200 254 ?
* i220.20.3.0 155.1.13.3 0 100 0 200 254 ?
*> 155.1.45.5 0 200 254 ?
* i222.22.2.0 155.1.13.3 0 100 0 200 254 ?
Network Next Hop Metric LocPrf Weight Path
*> 155.1.45.5 0 200 254 ?
Rack1R4(config)#do sh ip bgp neigh 155.1.146.1 adver
Rack1R4(config)#do sh ip bgp neigh 155.1.146.1 adver
BGP table version is 18, local router ID is 150.1.4.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 28.119.16.0/24 204.12.1.254 0 0 54 i
*> 28.119.17.0/24 204.12.1.254 0 0 54 i
*> 112.0.0.0 204.12.1.254 0 54 50 60 i
*> 113.0.0.0 204.12.1.254 0 54 50 60 i
*> 114.0.0.0 204.12.1.254 0 54 i
*> 115.0.0.0 204.12.1.254 0 54 i
*> 116.0.0.0 204.12.1.254 0 54 i
*> 117.0.0.0 204.12.1.254 0 54 i
*> 118.0.0.0 204.12.1.254 0 54 i
*> 119.0.0.0 204.12.1.254 0 54 i
*> 155.1.0.0 0.0.0.0 32768 i
*> 205.90.31.0 155.1.45.5 0 200 254 ?
*> 220.20.3.0 155.1.45.5 0 200 254 ?
*> 222.22.2.0 155.1.45.5 0 200 254 ?
Total number of prefixes 14
Rack1R4(config)#
##################### and where the actual problem is , R1
Rack1R1(config-router)#do sh ip bgp
BGP table version is 15, local router ID is 150.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
* i28.119.16.0/24 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i28.119.17.0/24 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i112.0.0.0 54.1.1.254 0 100 0 54 50 60 i
*>i 204.12.1.254 0 100 0 54 50 60 i
* i113.0.0.0 54.1.1.254 0 100 0 54 50 60 i
*>i 204.12.1.254 0 100 0 54 50 60 i
* i114.0.0.0 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i115.0.0.0 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i116.0.0.0 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i117.0.0.0 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i118.0.0.0 54.1.1.254 0 100 0 54 i
Network Next Hop Metric LocPrf Weight Path
*>i 204.12.1.254 0 100 0 54 i
* i119.0.0.0 54.1.1.254 0 100 0 54 i
*>i 204.12.1.254 0 100 0 54 i
* i155.1.0.0 155.1.146.6 0 100 0 i
*>i 155.1.146.4 0 100 0 i
*> 205.90.31.0 155.1.13.3 0 200 254 ?
* i 155.1.45.5 0 100 0 200 254 ?
*> 220.20.3.0 155.1.13.3 0 200 254 ?
* i 155.1.45.5 0 100 0 200 254 ?
*> 222.22.2.0 155.1.13.3 0 200 254 ?
* i 155.1.45.5 0 100 0 200 254 ?
Rack1R1(config-router)# do sh ip bgp 112.0.0.0
BGP routing table entry for 112.0.0.0/8, version 4
Paths: (2 available, best #2, table Default-IP-Routing-Table)
Multipath: eBGP iBGP
Advertised to update-groups:
1 2
54 50 60, (Received from a RR-client)
54.1.1.254 (metric 2560002816) from 155.1.146.6 (150.1.6.6)
Origin IGP, metric 0, localpref 100, valid, internal, multipath
DMZ-Link Bw 250 kbytes
54 50 60, (Received from a RR-client)
204.12.1.254 (metric 2560002816) from 155.1.146.4 (150.1.4.4)
Origin IGP, metric 0, localpref 100, valid, internal, multipath, best
DMZ-Link Bw 12500 kbytes
Rack1R1(config-router)#do sh ip route 112.0.0.0
Routing entry for 112.0.0.0/8
Known via "bgp 100", distance 200, metric 0
Tag 54, type internal
Last update from 204.12.1.254 00:15:30 ago
Routing Descriptor Blocks:
204.12.1.254, from 155.1.146.4, 00:15:30 ago
Route metric is 0, traffic share count is 1
AS Hops 3
Route tag 54
* 54.1.1.254, from 155.1.146.6, 00:15:30 ago
Route metric is 0, traffic share count is 1
AS Hops 3
Route tag 54
Rack1R1(config-router)#
as you can see , the BGP process in R1 is receiving the correct DMZ-link bw but is not taking it into effect ...
can you please help me if i mised anything in my configuration ?
Solved! Go to Solution.
10-02-2013 05:26 AM
Hi,
Can you please double check you have a bandwidth value on ALL your BGP peering physical interfaces? And also can you include the running-config output from R1 for 'router bgp XXXX' as you haven't included that one (the others are there). Just to make sure you have 'bgp dmzlink-bw' configured on all those peerings and globally in the process - as it will still show it in the community output even if it's not working on it.
10-02-2013 05:26 AM
Hi,
Can you please double check you have a bandwidth value on ALL your BGP peering physical interfaces? And also can you include the running-config output from R1 for 'router bgp XXXX' as you haven't included that one (the others are there). Just to make sure you have 'bgp dmzlink-bw' configured on all those peerings and globally in the process - as it will still show it in the community output even if it's not working on it.
10-02-2013 06:03 PM
Hi Jamie
Great point , you mentioned configuring the DMZ-link bw globally and per neighbor , i knew it should only be on the border routers not across the iBGP neighbours ,however i decided trying to enable it globally on R1 and got the following message :
Rack1R1(config-router)# bgp dmzlink-bw
Rack1R1(config-router)#
*Sep 2 10:34:09.727: %FIB-4-UNEQUAL: Range of unequal path weightings too large for prefix 28.119.16.0/24. Some available paths may not be used.
Rack1R1(config-router)#do clear ip bgp *
Rack1R1(config-router)#
*Sep 2 10:37:25.443: %BGP-5-ADJCHANGE: neighbor 155.1.13.3 Down User reset
*Sep 2 10:37:25.443: %BGP-5-ADJCHANGE: neighbor 155.1.146.4 Down User reset
*Sep 2 10:37:25.447: %BGP-5-ADJCHANGE: neighbor 155.1.146.6 Down User reset
*Sep 2 10:37:25.491: %BGP-5-ADJCHANGE: neighbor 155.1.146.4 Up
*Sep 2 10:37:25.491: %BGP-5-ADJCHANGE: neighbor 155.1.146.6 Up
*Sep 2 10:37:26.695: %BGP-5-ADJCHANGE: neighbor 155.1.13.3 Up
Rack1R1(config-router)#
*Sep 2 10:37:26.843: %FIB-4-UNEQUAL: Range of unequal path weightings too large for prefix 28.119.16.0/24. Some available paths may not be used.
Rack1R1(config-router)#do sh ip bgp 112.0.0.0
then found the following post :
http://ieoc.com/forums/p/21866/182741.aspx
which advises to decreas the weighting range by increasing R6 interface bandwidth :
Rack1R6(config-if)#do sh int ser 0/0/0
Serial0/0/0 is up, line protocol is up
Hardware is GT96K Serial
Internet address is 54.1.1.6/24
MTU 1500 bytes, BW 4000 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation FRAME-RELAY, loopback not set
Keepalive set (10 sec)
CRC checking enabled
LMI enq sent 108550, LMI stat recvd 108551, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 1023 LMI type is CISCO frame relay DTE
FR SVC disabled, LAPF state down
Broadcast queue 0/64, broadcasts sent/dropped 23622/0, interface broadcasts 0
Last input 00:00:00, output 00:00:04, output hang never
Last clearing of "show interface" counters 1w5d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/1000/64/0 (size/max total/threshold/drops)
Conversations 0/1/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 3000 kilobits/sec
5 minute input rate 1000 bits/sec, 2 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
2766148 packets input, 196741763 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
413205 packets output, 16697965 bytes, 0 underruns
0 output errors, 0 collisions, 9 interface resets
382292 unknown protocol drops
382306 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
2 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
straight away the problem got disapeard :
Rack1R1(config-router)#do sh ip bgp 112.0.0.0
BGP routing table entry for 112.0.0.0/8, version 19
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Multipath: iBGP
Advertised to update-groups:
1 2
54 50 60, (Received from a RR-client)
155.1.146.4 from 155.1.146.4 (150.1.4.4)
Origin IGP, metric 0, localpref 100, valid, internal, multipath, best
DMZ-Link Bw 12500 kbytes
54 50 60, (Received from a RR-client)
155.1.146.6 from 155.1.146.6 (150.1.6.6)
Origin IGP, metric 0, localpref 100, valid, internal, multipath
DMZ-Link Bw 500 kbytes
Rack1R1(config-router)#
Rack1R1(config-router)#do sh ip route 112.0.0.0
Routing entry for 112.0.0.0/8
Known via "bgp 100", distance 200, metric 0
Tag 54, type internal
Last update from 155.1.146.6 00:08:52 ago
Routing Descriptor Blocks:
155.1.146.6, from 155.1.146.6, 00:08:52 ago
Route metric is 0, traffic share count is 1
AS Hops 3
Route tag 54
* 155.1.146.4, from 155.1.146.4, 00:08:52 ago
Route metric is 0, traffic share count is 48
AS Hops 3
Route tag 54
Rack1R1(config-router)#
sounds like 1:48 is the maximum weight difference range that the 12.4(24)T can tolerate, whereas before it was 12500/250 which is = 50 , hence unacceptabe for load sharing.
Thanks for your great point and help
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: