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connection resets happening to web services servers when clients uses load balanced url. Need help to capture traffic.
Hi,
I'm seeing complaints saying that there are intermittent resets happening when the client uses load balanced url. Out of 60 web request sent from clients in 30 minutes, 8 to 9 requests were getting dropped intermittently. And I'm asked to identify the issue with resets and root cause.
Here is the configuration of the VIP. can someone suggest me the best way to capture the traffic when the resets happen. Bear in mind, I cannot run tcpdump for all the 30 minutes as it could generate a huge log file or pcap file. Please suggest me the appropriate procedure or tcpdump commands that I can use to capture the traffic when resets happen and I can give them the reason behind the that resets - can use ringdump process (I don't know how to do it though). Please suggest. thanks.
ltm virtual vs_gpdef_app_amvescap_ha {
destination 10.196.1.15:http
ip-protocol tcp
mask 255.255.255.255
persist {
simple-18000 {
default yes
}
}
pool pool_GPDEF_app_amvescap_ha
profiles {
tcp-gccp { }
}
source 0.0.0.0/0
source-address-translation {
type automap
}
vs-index 66
}
ltm pool pool_GPDEF_app_amvescap_ha {
members {
10.194.232.127:http {
address 10.194.232.127
session monitor-enabled
state up
}
10.194.232.134:http {
address 10.194.232.134
session monitor-enabled
state up
}
}
monitor http
}
ltm profile tcp tcp-gccp {
abc enabled
ack-on-push disabled
app-service none
close-wait-timeout 5
cmetrics-cache enabled
congestion-control high-speed
defaults-from tcp
deferred-accept disabled
delayed-acks enabled
dsack disabled
ecn disabled
fin-wait-timeout 5
idle-timeout 2000
ip-tos-to-client 0
keep-alive-interval 1800
limited-transmit enabled
link-qos-to-client 0
max-retrans 8
md5-signature disabled
md5-signature-passphrase none
nagle enabled
pkt-loss-ignore-burst 0
pkt-loss-ignore-rate 0
proxy-buffer-high 16384
proxy-buffer-low 4096
proxy-mss disabled
proxy-options disabled
receive-window-size 32768
reset-on-timeout enabled
selective-acks enabled
send-buffer-size 32768
slow-start enabled
syn-max-retrans 3
time-wait-recycle enabled
time-wait-timeout 2000
timestamps enabled
verified-accept disabled
zero-window-timeout 20000
}
- natheCirrocumulus
You can get the BIG-IP to log why it's sent RSTs and that might help. See SOL13223: Configuring the BIG-IP system to log TCP RST packets
As another option this tcpdump command will only look for RST packets - this should show where the rst is coming from.
To view all packets that are traveling through the BIG-IP system that contain the RST flag, type the following command: tcpdump 'tcp[tcpflags] & (tcp-rst) != 0'
Hope this helps,
N
- newf5learnerNimbostratus
thanks. other than the command to capture the resets (the above command is not working - I tired multiple times on a busy LTM), can you please suggest how to capture traffic using some compound statements using source, destination servers and on port 80.
I have even tried this
tcpdump '( tcp[tcpflags] & (tcp-rst) != 0) and host 10.196.1.119' but I'm seeing no traffic even though I reset the connection from browser. tcpdump -ni 0.0 src host 10.194.232.2 and '(dst host 10.194.232.127 or dst host 10.194.232.134)'
10.194.232.2 is the Internal self IP address which is interacting with servers. however its capturing the health monitor traffic also. Please suggest me how to filter out only my active client connection related traffic but not the health monitor one.
Please suggest. thanks.
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