04-20-2007 05:38 PM - edited 03-03-2019 04:38 PM
hello
I am trying to debug why my load balancing is not giving me a 100% of the bandwidth, i tried few commands, if some one please explain what they mean and if there is something wrong in their output:
Router#sh cef not-cef
CEF Packets passed on to next switching layer
Slot No_adj No_encap Unsupp'ted Redirect Receive Options Access Frag
RP 1231 0 3687843 13 290906 0 0 0
Router#sh cef drop
CEF Drop Statistics
Slot Encap_fail Unresolved Unsupported No_route No_adj ChkSum_Err
RP 7308 0 0 6 0 0
#sh ip cef receive
Apr 21 00:57:54.663: CEF-Receive: Packet for 65.55.251.108 -- unsupported featur
e
Apr 21 00:57:54.663: CEF-Receive: Not supported for 208.98.1.46 thru Dialer5 - r
eceive
Apr 21 00:57:54.663: CEF-Receive: Packet for 208.98.1.46 -- unsupported feature
Apr 21 00:57:54.663: CEF-Receive: Not supported for 208.98.1.46 thru Dialer5 - r
eceive
Apr 21 00:57:54.663: CEF-Receive: Packet for 208.98.1.46 -- unsupported feature
Apr 21 00:57:54.663: CEF-Receive: Not supported for 209.73.166.140 thru Dialer2
- receive
04-21-2007 12:48 AM
Hi there,
For CEF the Unsupported feature indicates that for the packet received the adjacency route information was dropped due to unsupported features.
By default, Cisco IOS software switches packets using the next fastest switching path (such as optimum, fast, or process switching) when CEF does not support a feature or encapsulation, and i think thats why your load balancing has problems.
For example since Cisco IOS Software Releases 11.2, CEF didn't support these features (I am trying to find out an updated list for you):
* Policy routing
* Network Address Translation (NAT)
* Access lists on the GSR
* Multipoint PPP
* SMDS
* Token Ring
* ATM dixie
* Inter-Switch Link (ISL)
http://www.cisco.com/en/US/products/sw/iosswrel/ps1824/products_feature_guide09186a0080087adc.html
HTH,
Mohammed Mahmoud.
04-21-2007 05:54 AM
Thanks so much mohammed, i finally got a reply for this...
my version is 12.4, i am using 3845 router.
do you have any idea how to overcome this problem? what makes a packet supported feature and another not supported?
i need a solution if you have any idea please let me know.
thanks.
04-21-2007 07:56 AM
Hi Baha,
Kindly post your configuration in order to think it out.
BR,
Mohammed Mahmoud.
04-21-2007 09:25 AM
Hello Mohammed, thanks for your concern, here is the cfg:
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
boot-start-marker
boot-end-marker
!
enable secret xxx
!
aaa new-model
!
!
aaa authentication login default local
!
aaa session-id common
!
resource policy
!
ip subnet-zero
ip cef
ip cef load-sharing algorithm original
!
ip domain name xx.xx.xx.xx
ip name-server xx.xx.xx.xx
vpdn enable
!
!
username xxxx password 0 xxxx
!
!
interface GigabitEthernet0/0
description $ETH-LAN$$ETH-SW-LAUNCH$$INTF-INFO-GE 0/0$
ip address 10.10.10.1 255.255.255.0 secondary
ip address xxx.xx.xx.xx 255.255.255.248
ip nat inside
ip tcp adjust-mss 1452
load-interval 30
duplex auto
speed auto
media-type rj45
negotiation auto
!
interface GigabitEthernet0/1
ip address 192.168.0.1 255.255.0.0
ip nat inside
ip tcp adjust-mss 1452
duplex auto
speed auto
media-type rj45
negotiation auto
!
interface ATM0/1/0
bandwidth 1088
no ip address
no atm ilmi-keepalive
dsl operating-mode auto
hold-queue 224 in
pvc 0/35
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
!
interface ATM0/2/0
bandwidth 1088
no ip address
no atm ilmi-keepalive
dsl operating-mode auto
hold-queue 224 in
pvc DSL 0/35
encapsulation aal5mux ppp dialer
dialer pool-member 2
!
!
interface ATM0/3/0
bandwidth 1088
no ip address
logging event atm pvc state
no atm ilmi-keepalive
dsl operating-mode auto
hold-queue 224 in
pvc 0/35
encapsulation aal5mux ppp dialer
dialer pool-member 3
!
interface ATM3/0/0
bandwidth 1088
no ip address
no atm ilmi-keepalive
dsl operating-mode auto
hold-queue 224 in
pvc 0/35
encapsulation aal5mux ppp dialer
dialer pool-member 4
!
interface Dialer1
mtu 1492
bandwidth 1024
ip address negotiated
ip nat outside
encapsulation ppp
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication pap callin
ppp chap refuse
ppp pap sent-username xxx password 0 xxx
!
interface Dialer2
mtu 1492
bandwidth 1024
ip address negotiated
ip nat outside
encapsulation ppp
dialer pool 2
no cdp enable
ppp authentication pap callin
ppp chap refuse
ppp pap sent-username xxx password 0 xxxx
!
interface Dialer3
mtu 1492
bandwidth 1024
ip address negotiated
ip nat outside
encapsulation ppp
dialer pool 3
no cdp enable
ppp authentication pap callin
ppp chap refuse
ppp pap sent-username xxx password 0 xxx
!
interface Dialer4
mtu 1492
bandwidth 1024
ip address negotiated
ip nat outside
encapsulation ppp
dialer pool 4
dialer-group 4
ppp authentication pap callin
ppp chap refuse
ppp pap sent-username xxx password 0 xxx
!
ip classless
ip route 0.0.0.0 0.0.0.0 Dialer1
ip route 0.0.0.0 0.0.0.0 Dialer2
ip route 0.0.0.0 0.0.0.0 Dialer3
ip route 0.0.0.0 0.0.0.0 Dialer4
!
ip nat inside source route-map Connection_1 interface Dialer1 overload
ip nat inside source route-map Connection_2 interface Dialer2 overload
ip nat inside source route-map Connection_3 interface Dialer3 overload
ip nat inside source route-map Connection_4 interface Dialer4 overload
!
no logging trap
access-list 1 permit 192.168.0.0 0.0.255.255
access-list 1 permit 10.10.10.0 0.0.0.255
access-list 10 permit 10.10.10.9
access-list 101 permit ip 10.10.10.0 0.0.0.255 any
access-list 101 permit ip 192.168.0.0 0.0.255.255 any
dialer-list 1 protocol ip permit
snmp-server community xxx RO
!
route-map Connection_1 permit 10
match ip address 1
match interface Dialer1
!
route-map Connection_2 permit 10
match ip address 1
match interface Dialer2
!
route-map Connection_3 permit 10
match ip address 1
match interface Dialer3
!
route-map Connection_4 permit 10
match ip address 1
match interface Dialer4
!
04-22-2007 12:59 AM
Hi Baha,
why did you configure the "ip cef load-sharing algorithm original "
The following load-balancing algorithms are provided for use with CEF traffic. You select a load balancing algorithm with the ip cef load-sharing algorithm command.
?Original algorithm?The original CEF load-balancing algorithm produced distortions in load sharing across multiple routers because the same algorithm was used on every router. Depending on your network environment, you should select either the universal algorithm (default) or the tunnel algorithm.
?Universal algorithm?The universal load-balancing algorithm allows each router on the network to make a different load sharing decision for each source-destination address pair, which resolves load-sharing imbalances. The router is set to perform universal load sharing by default.
?Tunnel algorithm?The tunnel algorithm is designed to balance the per-packet load when only a few source and destination pairs are involved.
http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a0080430ac3.html
BR,
Mohammed Mahmoud.
04-22-2007 07:47 AM
Hello Mohammed,
i tried this ip cef load-sharing algorithm original, after many trials, now i removed this line, i still recieve many 'Unsupported feature' when i debug ip cef receive.
is it my router limitations?
does the rest of my config looks fine?
thanks for you help.
04-22-2007 11:05 AM
Hi Baha,
There is nothing wrong with your configuration.
May be the combination of your configuration (NAT, load-sharing and route-maps) have produced the unsupported feature. (Note that the unsupported feature packets are not dropped, they are normally fast switched which should not affect your BW utilization).
How are you testing your BW utilization ?
BR,
Mohammed Mahmoud.
04-22-2007 11:27 AM
hi
my BW utilization is about 25% - 30% for each line.
even when i try to download something when the 4 lines at 25-30%, i dont get much bandwidth (2-3kbyte/s) and the download stops usually.
if i immeadiatly remove the line from the Cisco Router, and plugged it to a normal ADSL modem, i get 100% of the bandwidth!
anyway to trace what's really happening?
is there a diffrent or better way for load sharing?
thanks.
04-22-2007 11:38 AM
Hi Baha,
I am really trying to help you out here, you are load-sharing per-destination which is fine with no problems, i am suspecting the MSS and MTU issue as it always affect the TCP performance.
interface GigabitEthernet0/0
ip tcp adjust-mss 1452
interface Dialer2
mtu 1492
BR,
Mohammed Mahmoud.
04-22-2007 12:54 PM
hello mohammed,
i put this:
ip tcp adjust-mss 1452
because people couldnt login to yahoo or MSN
any suggestions to change the value?
also any suggestions to change the MTU?
thanks!
04-23-2007 12:16 PM
Dear Baha,
The Dialer CEF feature is not supported when a static route is pointing to the Dialer without specifying a next hop IP address. When using the Cisco IOS Release 12.3(11)T and higher, the ppp ipcp default route command may be used in Dialer interface configuration mode to work around this restriction.
CEF was not supported over dialer interface (older IOS's)
Use the below URL for more information
Dialer10 is up (if_number 8)
Corresponding hwidb fast_if_number 8
Corresponding hwidb firstsw->if_number 8
Internet Protocol processing disabled
Interface is marked as point to point interface
Packets switched to this interface are dropped to the next slow path: Dialer
Hardware idb is Dialer10
Fast switching type 15, interface type 85
(the above line said the packets recieved over dialer interface will be switched to next level switching)
Please rate helpful posts.
Best Regards,
Mounir Mohamed
04-23-2007 12:39 PM
Dear Baha,
Please try the above solution and feedback us.
BR,
Mohammed Mahmoud.
04-23-2007 01:27 PM
hello mohammed,
i have added ppp ipcp route default in each dialer int..
nothing has changed!
#debug ip cef rec
.Apr 23 21:24:12.412: IP-CEF: Receive packet for 88.84.97.8 (process switch)
.Apr 23 21:24:12.412: CEF-Receive: Not supported for 216.34.130.245 thru Dialer3
- receive
.Apr 23 21:24:12.412: CEF-Receive: Packet for 216.34.130.245 -- unsupported feat
ure
.Apr 23 21:24:12.428: CEF-Receive: Not supported for 84.48.216.192 thru Dialer1
- receive
.Apr 23 21:24:12.428: CEF-Receive: Packet for 84.48.216.192 -- unsupported featu
re
.Apr 23 21:24:12.428: CEF-Receive: Not supported for 207.46.106.70 thru Dialer6
- receive
.Apr 23 21:24
i dont really care for this messgae as much as i am not getting my 100% of the bandwidth, so any suggestion what to change the values of MTU & MSS?
thanks again and really appreciate your help.
04-23-2007 02:10 PM
Dear Baha,
Did you route the default/static route to the next-hop, the PDF said the problem usually happen when the default/static routes pointing to the dialer interface
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