F5
September 24, 2024 ยท View on GitHub
Key Points
High end commercial load balancers. Expensive.
If you've worked in high scale enterprise you'll probably come across these or Citrix Netscalers or similar.
I ran 4 x F5 Big-IP 8900 (highest end single chassis units available) in dual HA configurations at each of 2 datacenters.
Types
- LTM - Local Traffic Manager - VIPs - local network load balancer - Big-IPs
- GTM - Global Traffic Manager - DNS GSLB - global server load balancer
- ASM - L7 HTTP FW
- EM - Enterprise Manager centralized management
- FirePro - being built in to ASM SSL VPN
Traffic Flow
Client => GTM (DNS) => LTM VIP => server
General
F5 command line is Redhat Linux (/etc/redhat-release exists but is empty).
Guy on F5 course said his company puts Checkpoint firewalls in front of their F5s. Wonder how much additional protection this is really giving them if they're just punching a hole for TCP 443 anyway...
Config from scratch
- Interfaces & Trunks
- VLANs
- Self IPs
- Routes (default and internal)
Syslog
To add syslog to F5:
bigpipe syslog remote server { host1 { host 10.x.x.x } host2 { host 10.x.x.x } }
or
b syslog include '"destination remote_server { tcp(\"xxx.xx.xx.xxx\" port (514));
tcp(\"xxx.xx.xx.xxx\" port (514));
};
log { source(local); filter(f_local0); destination(remote_server); };"'
b verify load
b load
bigpipe save
Misc
16384 default SYN Check Activation Threshold reminds me how Juniper SSGs aren't designed for this kind of web usage given they default to 128.
Share a * pool across 2 virtual servers.
BigPipe
bpsh - From advanced shell (linux) /usr/bin/bpsh, drops you in to a bigpipe shell. Can set this via web ui in user profile to drop user straight to bpsh only
bigtop to see real time sessions
b failover standby
b interface 1.2 disable
Dev Central
iRule editor from Dev Central
iRules are TCL code
For SSL must decrypt traffic on the BigIP to be able to inspect and use iRules
Use Network Failover on internal/external interfaces + Fail Safe to cause demotion to standby otherwise Active/Active split brain
Network Mirroring didn't work until after 1 double failover
Diagram
From the HariSekhon/Diagrams-as-Code repo:
F5 in Multi-Datacenter Java Stack

Ported from private Knowledge Base page 2011+