
The `logging discriminator` command in Cisco IOS allows for more granular configuration of [Syslog](/syslog) messages. This command enables you to filter syslog messages not only by [severity](/syslog-severity-levels) but also by matching specific strings within the messages. This can be particularly useful for maintaining a more focused and relevant set of logs. 

## Links

https://forum.networklessons.com/t/cisco-ios-syslog-messages/1179/53?u=lagapidis

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/esm/command/esm-cr-book/esm-cr-a1.html#wp1888787448

Syslog - logging discriminator

Serial - Data Terminal Equipment(DTE)

Serial - Link between two routers

Serial Interface - Clock Rate

Serial Interface default broadcast address

Session Border Controller

Session Initiation Protocol

Show open TCP-UDP ports on Cisco router

Spanning Tree Protocol (STP)

Spine and leaf architecture - connections to leaf switches

Spine and leaf architecture - connections to spine switches

Spine and leaf architecture - reducing latency

Split-horizon

StackWise - IOS upgrade switch reboot sequence

StackWise Virtual

Stackwise - IOS install mode vs bundle mode

Stackwise election process

Stackwise user priority

Static ARP entry for own IP address

Subscriber templating

Summarization

Supernetting

Switch High Availability and the Control Plane

Switch configuring a routed port

Switch high availability options

Switch protected port limitations

Switch protected port

Switching -  CEF Adjacency Table

Switching - CEF

Switching - Media Access Control (MAC) addresses

Switching - Process switching

Switching - backplane

Switching - cut through

Switching - fast switching

Switching - show cable-diagnostics

Switching - store and forward

Switching - switch fabric

Switching - switched virtual interface (SVI)

Switching - switchport autostate command

Switching

Switchport - IEEE 802.1q

Switchport - ISL

Switchport - show vlan internal usage

Switchport access

Switchport modes

Switchport trunk configuration ignores access commands

Switchport trunk encapsulation

Switchport trunk

Symmetric Digital Subscriber Line (SDSL)

Syslog - Logging buffered command

Syslog - terminal monitor

Syslog relay or proxy

Syslog severity levels

Syslog

TCP - Congestion control

TCP - Determining the MSS

TCP - Header

TCP - SEQ and ACK values

TCP - Slow start

TCP - Three-way handshake

TCP - Urgent pointer field

TCP - Window Size Scaling

TCP - factors affecting segment size

TCP - role of checksum field

TCP IP Model

TCP MSS and window size

TCP RST flag

TCP SYN timeout

TCP header options

TCP phantom byte

TFTP

Tcl Shell

Telnet

Time to live

Time-based Access List (ACL) on Cisco IOS XR

Traceroute - Interpreting output

Traceroute asterisk and !H responses

Traceroute

Transparent Cisco IOS Firewall use cases

Transport Layer port number

Troubleshooting - using Telnet to test transport layer ports

Troubleshooting a slow network

Troubleshooting high CPU and memory usage on a switch

UDP - Header

UDP - Maximum Datagram Size

Unicast Reverse Path Forwarding (uRPF)

Unicast traffic

Unknown unicast traffic

Upgrade your R&S skills to modern networking

VACL - Changes to ACL are active immediately

VACL - use cases

VACL vs ACL

VLAN - Extended Range

VLAN - Native VLAN best practices

VLAN - Native VLAN on a router on a stick

VLAN - Private VLAN

VLAN - QinQ troubleshooting

VLAN - VLAN IDs 0 and 4095