ASUS STP Operation Mode

[Igor]

Do I understand correctly that the Asus router uses the classic Spanning Tree Protocol (STP) and not Rapid STP (RSTP) and Multiple STP (MSTP)?

 

[eibgrad]

That's what it reports (STP) under LAN > Switch Control.

P.S. robocfg reports it as well.

robocfg show

Not unless it's reporting *generically* STP, but the actual implementation differs (seems unlikely).

 

[heysoundude]

For anyone following along at home interested in network topology and optimisation

Spanning Tree Path Cost Value and How is Spanning Tree Path Cost Value Calculated

This lesson explains Spanning Tree Path Cost Value and How is Spanning Tree Path Cost Value Calculated

www.omnisecu.com

and

Spanning Tree Protocol - Wikipedia

en.wikipedia.org

Not something to be too concerned with in most cases if you're Cat5e compliant (and above) and 1Gbps throughout, but the first link shows why it's time to retire any 10/100 switching you're still using, especially if you're closer to 1Gbps connection to WAN.

 

[ColinTaylor]

Do I understand correctly that the Asus router uses the classic Spanning Tree Protocol (STP) and not Rapid STP (RSTP) and Multiple STP (MSTP)?

Turn on Wireshark and see what it says. For my RT-AX86U it's normal STP with a hello time of 2 seconds. That said, if you look in the syslog you can see that it reacts to topology changes pretty quickly.

but the first link shows why it's time to retire any 10/100 switching you're still using, especially if you're closer to 1Gbps connection to WAN.

That's not what that article is demonstrating.

 

[Igor]

For me, important information was "RSTP was designed to be backward-compatible with standard STP" and "a network of connected layer-2 bridges".

robocfg reports it as well.

ASUSWRT-Merlin RT-AC68U 386.5_2
RT-AC68U# robocfg show
enabled stp

ASUSWRT-Merlin RT-AX68U 386.5_2
RT-AX68U# robocfg show
-sh: robocfg: not found

Thanks to all!
I will rebuild my network so that the CISCO switches see each other directly, and the connected LAN ports of the ASUS routers are behind the switches - router(STP) - switch(RSTP) - switch(RSTP) - router(STP). Now I have switch(RSTP) - router(STP) - router(STP) - switch(RSTP). After the rebuilding, it will be possible to introduce additional connections between switches and LAN ports of routers with a more efficient RSTP.

Why do I need it? Don't ask me, I don't know yet

 

[ColinTaylor]

ASUSWRT-Merlin RT-AX68U 386.5_2
RT-AX68U# robocfg show
-sh: robocfg: not found

Use brctl show and brctl showstp br0

Also:

# tcpdump -i eth1 llc
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 262144 bytes
20:17:15.542196 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:17.542217 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:19.542169 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:21.542187 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:23.542171 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:25.542197 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:27.542195 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:29.542204 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:31.542214 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35
20:17:33.542197 STP 802.1d, Config, Flags [none], bridge-id 8000.f0:2f:74:92:37:d8.8004, length 35