Network - BUM Traffic

Unicast traffic

VXLAN - MP-BGP EVPN and Multicast

Tags #unknown_unicast #unicast 

Unknown unicast traffic is [Unicast traffic](/unicast-traffic) for which the [switches](/switching) in the network have not yet learned the port to which the destination [MAC address](/mac-address) belongs.  When the destination MAC address is not found within the [MAC address table](/mac-address-table) of a switch, such a frame is sent out of all ports of the switch except the one on which the frame arrived.  

Once the destination device responds, its MAC address is recorded in the MAC address table, and any traffic destined to that device is no longer considered unknown unicast, but simply unicast.

## Links

https://www.cisco.com/en/US/docs/general/Test/dwerblo/broken_guide/blocking.html#wp1035969

Unknown unicast traffic

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 - logging discriminator

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)

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

VLAN Access Lists

VLAN Mapping

VLAN SVI status

VLAN Tag

VLAN Trunk interfaces missing in show vlan output

VLAN control frames

VLAN

VLANs - 802.1Q tunneling (QinQ)

VLANs - Dynamic VLAN membership (VMPS)

VLANs - QinQ and CDP

VLANs - Vlans allowed and active in management domain

VLANs - when a tagged frame arrives on an access port

VLANs SVI

VPN - IKEv2 peer address of 0.0.0.0 0.0.0.0

VPN - Interesting Traffic

VPN - NAT Exemption

VPN - crypto keepalive

VPN - default gateway for site to site VPN

VPN - default gateway of VPN client

VPN - split tunneling

VPN DVTI tunnel source

VRF - Definition mode

VRF - VPNv4 address

VRF capability vrf-lite command

VRF lite route leaking

VRF sharing across multiple routers

VRF use cases

VRRP - Virtual IP doesn't respond to pings

VRRP - load balancing

VRRP - support for authentication

VRRP - using the same ID on different interfaces

VRRP - using the same ID on subinterfaces

VRRP on sub-interfaces

VTP - Client can't modify VLANs

VTP - Code Field

VTP - Multiple Servers with VTP version 2

VTP - Per interface configuration

VTP - Pruning the Extended VLAN ID Range

Unknown unicast traffic

Links

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