Contents
Does STP Work on access ports?
NTP requires bi-directional access on port 123 because the NTP RFC specifies the following regarding the source port of the client: When operating in symmetric modes (1 and 2), this field must contain the NTP port number PORT (123) assigned by the IANA.
Why STP is required when VLANs span access layer switches?
You may need to implement STP for several reasons: When a VLAN spans access layer switches to support business applications. To protect against user-side loops. Even if the recommended design does not depend on STP to resolve link or node failure events, STP is required to protect against user-side loops.
Which ones are correct STP port roles?
RSTP assigns slightly different roles to ports. Those roles include root, designated, alternate, backup, and disabled. Root and designated are still the roles that reach the state of forwarding. The role of Desg and Root port is forwarding traffic.
What is the command to know the switch port is layer 3 or layer 2?
Table 17-4 Chapter 17 Configuration Command Reference
| Command | Description |
|---|---|
| [no] switchport | Layer 3 switch subcommand that makes the port act as a Layer 2 port (switchport) or Layer 3 routed port (no switchport) |
What happens when STP is disabled?
Disabling Spanning Tree Protocol (STP) can cause Broadcast Storms and Layer 2 Switching Loops, which can make your network down within a short span of time.
How do I enable STP?
Step 1 – enabling STP switch>enable – It is used to enter privileged mode. switch#configure terminal – It is used to enter the switch management interface. switch(config)#spanning-tree vlan vlan-id – We use this command to enable the spanning tree protocol on our VLAN.
What are the five STP port states?
The ports on a switch with enabled Spanning Tree Protocol (STP) are in one of the following five port states.
- • Blocking.
- • Listening.
- • Learning.
- • Forwarding.
- • Disabled.
How does STP decide which port to block?
All switches that are participating in STP exchange BPDU frames to determine which switch has the lowest bridge ID (BID) on the network. After the root bridge has been determined, the STA calculates the shortest path to the root bridge. Each switch uses the STA to determine which ports to block.
Can 2 VLANs communicate with each other?
Two separate VLANs must communicate through a layer-3 device, like a router. Devices on a VLAN communicate with each other using layer-2. Layer-3 must be used to communicate between separate layer-2 domains.
Which is best RSTP or per VLAN Rapid STP?
Per-VLAN Rapid STP (PVRSTP) is a Cisco enhancement of RSTP. This version creates root bridges for each VLAN, allowing all links to be active in some way. This is the recommended version in an all-Cisco network. Multiple STP (MST) is also an industry standard.
Do you need VSS for a VLAN spanning network?
There is another issue with this network. Spanned VLANs lead to larger layer-2 networks. This generally means more flooding and broadcast traffic. One way to tune this is to use VSS at the distribution layer. This still allows VLAN spanning but includes some improvements to the topology.
Why does a switch port belong to a VLAN?
A switch port can belong to a VLAN. Unicast, broadcast, and multicast packets are forwarded and flooded out ports in the same VLAN. VLANs can also be used to enhance performance by reducing the need to send broadcasts and multicasts to unnecessary destinations.
Can a port in access mode have more than one VLAN?
A port in access mode can have only one VLAN configured on the interface which can carry traffic for only one VLAN. The options are: vlan-id – Specifies the VLAN to which the port is configured. none – Specifies that the access port cannot belong to any VLAN.