Is this a BUG or ASUS design flaw?

[hasuboy]

hello everyone, i met a strange problem when i using asus router, the following is my network topology:
[URL="http://forums.smallnetbuilder.com/attachment.php?attachmentid=3211&stc=1&d=1422348820[/URL]

i discussed with my friends, we think this network structure is no problem. But the actual result is PING router(192.168.2.1) from PC is about 50%-80% loss, at the same time the router WAN PPPoE connection disconnect every few minutes then reconnect. I feel the whole network is paralyzed, just like the broadcast storm.

the strange thing is if i manually disconnect the PPPoE connection, let the router will no longer automatically reconnect, here the network will return to normal, i mean now PING router from PC will not loss packets. Once the PPPoE connection recovery, the network will start paralysis.

now you may want to ask me why not directly connected to router WAN port and ZTE F660, and must go through switch? I just want to say i do this for some reasons, i don't want to do many description at this point. In short, i think my network struture does not exist loop. In my opinion, the 2 vlan on the switch are unnecessary, i even doubted the network loop really exist, but i did not see it, so i divided the 2 vlan later.

I finally want to say perhaps the most important. I tried to use some other routers to replace AC87U for test, like tplink, dlink, buffalo, cisco, etc. Surprising is that they don't have any problem in this network structure, even i tried to delete the 2 vlan on the switch, the result is still all normal. It's interesting that i also tried to use a AC68U for test, the result is the same with AC87U.

I really don't understand why does this work? is this a BUG or design flaws? now i am very confused and i hope to get some useful help. thanks in advance.

 

[jspuds]

Why have you got both a LAN & WAN connection from the 87u, disconnect one and see how you get on?

 

[KGB7]

This is what we call a User Design Flaw.

Turn DHCP ON on the ZTE and remove the LAN cable from Asus router.

 

[bits]

I don't know exactly why it fails but my guess is:

Mac address on switch ports is the same and causes some issue where Asus choose route interface by upstream interface mac address. Other brands might use destination Mac to chose interface.

Get the managed switch to show a different Mac address per vlan?

PS not unlike android assuming any wireless access point with the same Mac is the same access point.
Eg if you have 2.4ghz and 5ghz on same Mac but different ssid, android will only "see" 1 access point at random.
While using the same Mac should technically not cause an issue the fact is only 1 device on a network should have any Mac address and software may behave unexpectedly if duplicate macs are used/seen for different connections.

 

[hasuboy]

Why have you got both a LAN & WAN connection from the 87u, disconnect one and see how you get on?

because my ZTE660(FTTH ONT) is set to bridge mode, so need a router to establish a PPPoE connection.

 

[hasuboy]

This is what we call a User Design Flaw.

Turn DHCP ON on the ZTE and remove the LAN cable from Asus router.

i was also forced to do so, because my ZTE660 only have 1 GE port(3 FE port) and i set it in bridge mode, this need a router to establish PPPoE connection(in fact, i need to connect more than one router on the switch). If i do that as you say, unless i establish a PPPoE connnection on my PC, otherwise how do i access the internet?

 

[hasuboy]

I don't know exactly why it fails but my guess is:

Mac address on switch ports is the same and causes some issue where Asus choose route interface by upstream interface mac address. Other brands might use destination Mac to chose interface.

Get the managed switch to show a different Mac address per vlan?

PS not unlike android assuming any wireless access point with the same Mac is the same access point.
Eg if you have 2.4ghz and 5ghz on same Mac but different ssid, android will only "see" 1 access point at random.
While using the same Mac should technically not cause an issue the fact is only 1 device on a network should have any Mac address and software may behave unexpectedly if duplicate macs are used/seen for different connections.

thanks for your reply, i need to rethink according to your theory

 

[KGB7]

i was also forced to do so, because my ZTE660 only have 1 GE port(3 FE port) and i set it in bridge mode, this need a router to establish PPPoE connection(in fact, i need to connect more than one router on the switch). If i do that as you say, unless i establish a PPPoE connnection on my PC, otherwise how do i access the internet?

Dont set the ZTE660 in to a bridge mode. Let it do the job its designed to do in the first place. You making the issue more complicated then it needs to be for no reason at all.

Then set the AC68 as AP if you only need wifi access from it.

Then PC1 will get a LAN IP from ZTE and so will the rest of the LAN devices that are connected to the switch.

 

[ngerasimatos]

Dont set the ZTE660 in to a bridge mode. Let it do the job its designed to do in the first place. You making the issue more complicated then it needs to be for no reason at all.

Then set the AC68 as AP if you only need wifi access from it.

Then PC1 will get a LAN IP from ZTE and so will the rest of the LAN devices that are connected to the switch.

Yeah, this is correct. You are making things over complicated for a home network. You only need a single router to serve DHCP and the wireless AP.