F5 - Load Balancer Commands

F5 BIG-IP Load Balancer Commands

f5 bigip cheatsheet command

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tmsh Command Reference

Enter tmsh from bash:

tmsh

Pool Commands

Command	Description
show ltm pool	List all pools with status
show ltm pool [pool-name]	Detailed pool info
show ltm pool [pool-name] members	Pool member status
list ltm pool [pool-name]	Pool configuration
modify ltm pool [pool-name] members modify { [member]:443 { state user-down } }	Disable member
modify ltm pool [pool-name] members modify { [member]:443 { state user-up } }	Enable member

Virtual Server Commands

Command	Description
show ltm virtual	List all virtuals with status
show ltm virtual [vs-name]	Detailed virtual info
list ltm virtual [vs-name]	Virtual configuration
show ltm virtual [vs-name] profiles	Applied profiles
show ltm virtual [vs-name] rules	Applied iRules

Node Commands

Command	Description
show ltm node	List all nodes
show ltm node [node-ip]	Node detail
modify ltm node [node-ip] state user-down	Force node offline
modify ltm node [node-ip] state user-up	Bring node online

Connection Commands

Command	Description
show sys connection	All current connections
show sys connection cs-server-addr [ip]	Connections to specific server
show sys connection cs-client-addr [ip]	Connections from specific client
show sys connection virtual [vs-name]	Connections for virtual
delete sys connection all	Clear all connections (use cautiously)
show sys connection count	Connection summary

Monitor Commands

Command	Description
show ltm monitor	List monitors
list ltm monitor [type] [name]	Monitor configuration
show ltm pool [pool-name] members field-fmt	Member monitor status

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Persistence Commands

Command	Description
show ltm persistence persist-records	View persistence table
delete ltm persistence persist-records pool [pool-name]	Clear persistence for pool
show ltm persistence persist-records virtual [vs-name]	Persistence for virtual

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Troubleshooting Workflows

Pool Member Down

1. Check member status

   show ltm pool [pool-name] members
   

   Look at State and Monitor-Status

2. Check monitor configuration

   list ltm pool [pool-name] monitor
   list ltm monitor [type] [monitor-name]
   

3. Test connectivity from F5

   # From bash
   curl -v http://[member-ip]:[port]/health
   nc -zv [member-ip] [port]

4. Check member’s specific monitor status

   show ltm pool [pool-name] members [member:port] field-fmt
   

Connection Distribution

1. Check current connections per member

   show ltm pool [pool-name] members field-fmt
   

   Look at Cur Sessions column

2. Verify load balancing method

   list ltm pool [pool-name] load-balancing-mode
   

3. Check persistence

   list ltm virtual [vs-name] persist
   show ltm persistence persist-records virtual [vs-name]
   

SSL Issues

show ltm clientssl-profile [profile-name]
list ltm profile client-ssl [profile-name]
show sys crypto cert [cert-name]
show sys crypto cert-order [vs-name]

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System Commands

Command	Description
show sys version	BIG-IP version
show sys hardware	Hardware info
show sys performance throughput	Traffic stats
show sys failover	HA status
show cm sync-status	Config sync status
save sys config	Save running config

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Quick Reference

Check Why Traffic Isn’t Flowing

show ltm virtual [vs-name]           # VS enabled?
show ltm pool [pool-name]            # Pool has available members?
show ltm pool [pool-name] members    # Members up?
show sys connection virtual [vs]     # Connections arriving?

Save and Sync

save sys config
run cm config-sync to-group [device-group]