Forum Discussion
TCP Connection Reset between VIP and Client
Topology:
Pulse Authentication Servers <--> F5 <--> FORTIGATE <--> JUNOS RTR <--> Internet <--> Client/users.
Background:
Clients on the internet attempting to reach a VPN app VIP (load-balances 3 Pulse VPN servers). Nodes + Pool + Vips are UP. I manage/configure all the devices you see. No SNAT/NAT: due to client requirement to see all IP's on Fortigate logs. Client rejected solution to use F5 logging services.
I successfully assisted another colleague in building this exact setup at a different location. For some odd reason, not working at the 2nd location I'm building it on. Compared config scripts. NO differences. Very puzzled. Concerned about FW rules on Fortigates so I am in the middle of comparing the Fortigate FW rule configurations at both locations, but don't let that persuade you.
Results:
Client can't reach VIP using pulse VPN client on client machine. Client also failed to telnet to VIP on port 443, traffic is reaching F5 --> leads to connection resets. I can successfully telnet to pool members on port 443 from F5 route domain 1.
Configuration:
ltm monitor https MONITOR_HTTPS_EXAMPLE {
adaptive disabled
cipherlist DEFAULT:+SHA:+3DES:+kEDH
compatibility enabled
defaults-from https
destination *:*
interval 10
ip-dscp 0
recv "200 OK"
recv-disable 500
send "GET /dana-na/healthcheck/healthcheck.cgi HTTP/1.1\r\nHost: newark.dxc.technology\r\nConnection: Close\r\n\r\n"
time-until-up 0
timeout 31
}
ltm node NODE1 {
address 30.1.1.138%1
}
ltm node NODE2 {
address 30.1.1.139%1
}
ltm node NODE3 {
address 30.1.1.140%1
}
ltm persistence source-addr source-addr-2700 {
app-service none
match-across-services enabled
mirror enabled
timeout 2700
}
ltm pool POOL_EXAMPLE {
allow-nat no
allow-snat no
load-balancing-mode least-connections-member
members {
NODE1:https {
address 30.1.1.138%1
session monitor-enabled
state up
}
NODE2:https {
address 30.1.1.139%1
session monitor-enabled
state up
}
NODE3:https {
address 30.1.1.140%1
session monitor-enabled
state up
}
}
monitor MONITOR_HTTPS_EXAMPLE
}
ltm virtual VIP_EXAMPLE {
destination 40.1.1.30%1:https
ip-protocol tcp
mask 255.255.255.255
persist {
source-addr-2700 {
default yes
}
}
pool POOL_EXAMPLE
profiles {
fastL4 { }
}
source 0.0.0.0%1/0
translate-address enabled
translate-port enabled
vs-index 4
}
net route-domain SE_EXT_DMZ {
description SE_EXT_DMZ
id 1
vlans {
SERVER-VLAN-EXAMPLE
VIP-VLAN-EXAMPLE
}
}
net self HA_IP {
address 10.10.0.1/29
traffic-group traffic-group-local-only
vlan HA_VLAN
}
net self VIP-VLAN-EXAMPLE_NON_FLOATER {
address 40.1.1.5%1/24
allow-service {
default
}
traffic-group traffic-group-local-only
vlan VIP-VLAN-EXAMPLE
}
net self SERVER-VLAN-EXAMPLE_NON {
address 30.1.1.133%1/25
allow-service {
default
}
traffic-group traffic-group-local-only
vlan SERVER-VLAN-EXAMPLE
}
net self SERVER-VLAN-EXAMPLE {
address 30.1.1.132%1/25
allow-service {
default
}
floating enabled
traffic-group traffic-group-1
unit 1
vlan SERVER-VLAN-EXAMPLE
}
net self VIP-VLAN-EXAMPLE {
address 40.1.1.4%1/24
allow-service {
default
}
floating enabled
traffic-group traffic-group-1
unit 1
vlan VIP-VLAN-EXAMPLE
}
net trunk F5_VLAN_TRUNK {
bandwidth 20000
cfg-mbr-count 2
id 0
interfaces {
5.0
6.0
}
lacp enabled
mac-address f4:15:63:ee:7c:09
media 10000
working-mbr-count 2
}
net vlan VIP-VLAN-EXAMPLE {
if-index 848
interfaces {
F5_VLAN_TRUNK {
tagged
}
}
tag 461
}
net vlan SERVER-VLAN-EXAMPLE {
if-index 864
interfaces {
F5_VLAN_TRUNK {
tagged
}
}
tag 457
}
TCPDUMP
See next post
What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
I would do the following then test:
- Change the VIP to use SNAT. Test.
- If it works, reverse the VIP configuration in step 1 (e.g. no SNAT)
- Disable all pool members in POOL_EXAMPLE except for 30.1.1.138
- Change the gateway for 30.1.1.138 to 30.1.1.132. Test.
- AceDawg1Nimbostratus
What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
- AceDawg1Nimbostratus
I would do the following then test:
- Change the VIP to use SNAT. Test.
- If it works, reverse the VIP configuration in step 1 (e.g. no SNAT)
- Disable all pool members in POOL_EXAMPLE except for 30.1.1.138
- Change the gateway for 30.1.1.138 to 30.1.1.132. Test.
- AceDawg1Nimbostratus
In addition, do you have a VIP configured for port 4500? Noticed in the traffic capture that there is traffic going to TCP port 4500:
18:01:03.427463 IP (tos 0x0, ttl 64, id 5134, offset 0, flags [DF], proto TCP (6), length 60) 30.1.1.133.51704 > 30.1.1.139.4500: Flags [S], cksum 0x609e (incorrect -> 0x57ee), seq 2071882144, win 14600, options [mss 1460,sackOK,TS val 4213873347 ecr 0,nop,wscale 7], length 0 out slot1/tmm0 lis=
- hmian_178112Nimbostratus
THank you AceDawg, your first answer was on point and resolved the issue.
Comment made 4 hours ago by AceDawg 202What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
- AceDawg1Nimbostratus
Excellent! I'll post said response as an answer to your question.
Could you "Accept" for me please?
What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
I would do the following then test:
- Change the VIP to use SNAT. Test.
- If it works, reverse the VIP configuration in step 1 (e.g. no SNAT)
- Disable all pool members in POOL_EXAMPLE except for 30.1.1.138
- Change the gateway for 30.1.1.138 to 30.1.1.132. Test.
- hmian_178112Nimbostratus
This was it, I had to change the Gateway for the POOL MEMBERS to the F5 SELF IP rather than the Fortigate Firewall upstream because we are not using SNAT.
- AceDawg1Nimbostratus
What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
I would do the following then test:
- Change the VIP to use SNAT. Test.
- If it works, reverse the VIP configuration in step 1 (e.g. no SNAT)
- Disable all pool members in POOL_EXAMPLE except for 30.1.1.138
- Change the gateway for 30.1.1.138 to 30.1.1.132. Test.
- hmian_178112Nimbostratus
This was it, I had to change the Gateway for the POOL MEMBERS to the F5 SELF IP rather than the Fortigate Firewall upstream because we are not using SNAT.
- hmian_178112Nimbostratus
It was the first response. Not the one you posted -->
I'll accept once you post the first response you sent (below)
Comment made 5 hours ago by AceDawg 204 What are the Pulse/VPN servers using as their default gateway? They should be using the F5 if SNAT is not in use to avoid asymmetric routing.
- AceDawg1Nimbostratus
Mea culpa. I added both answers/responses as the second provides a quick procedure on how things should be configured.
Many thanks.
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