Help with networking issue

Maic

Hey guys,

I need some advice on a problem I am currently having and been struggling with it for some time now. A lot of time has been spent trying to solve it and still cannot get to the bottom of it.

[THE SETUP]
A friend has a building with 14 apartments and a 250 UPC line. We are using the CISCO EPC 3925 as a modem + router. From the UPC router we have a 1000mb line to a brand new CISCO SG300 managed switch. From there there are 14 x 100mb lines that goes into apartments connected to Zyxel N300 AP.

UPC CABLE => UPC EPC 3925 modem => CISCO SG300 => 14 x Zyxel N300 AP

The UPC modem acts as a DHCP server on 192.168.1.1. This will give IP addresses from .20 to 255. I do reserve the first 20 for the static Access Points Ips.

The CISCO SG300 is brand new as we wanted to limit the bandwith to each apartment to 30mbs. The bandwidth limit is ON, working and applied to the 14 apartment ports. Also the switch is used as Level 3.

The Zyxel N300 Access Points are configured with static IPS (from 1.2 - 1.15)

IP: 192.168.1.2 - 15
Subnet: 255.255.255.0
DNS: 192.168.1.1

On average, in each apartment there could be 3 devices connected at the same time.

[THE PROBLEM]
The internet connection on the WHOLE network goes down randomly. Its like the UPC router is getting blocked or something. It does allocated IPs but no internet connection. Trying to load a page ends up in "DNS Probe started / DNS Probe finished - no internet"
Surprisingly trying to load the UPC config page end up in a router restart (all leds blinks orange), "Network changed" message and everything returns to normal. This could have been a coincidence or something

The Cisco switch is configured as Level 3 because I wanted to make it a DHCP server but I got lost in configuration - I know networking but not at that level

Also checking the Zyxel logs there are some warns but I dont think this is making the UPC switch to hang. I could look into the c code but cannot find it

"WAP3205v2 user.warn kernel: drivers/net/wireless/rt2860v2_ap/../rt2860v2/ap/ap_sync.c:1655 assert regclassfailed"
"WAP3205v2 user.warn kernel: rt2860v2_ap: module license 'unspecified' taints kernel."
"WAP3205v2 user.info kernel: 0>Qidx(0), not enough space in MgmtRing, MgmtRingFullCount=373!"

Do you guys think its the UPC router ? Do you think its struggling with DHCP ? Is the setup OK?
Any tips on configuring CISCO Switch as DHCP much appreciated.

The UPC technicians were there many times / coudnt see anything / the did router restart / they changed the router multiple times as well
Zyxel has no clue about the warnings
A lot of people are unfriendly about the internet connection

ED E

First off the 3925 needs active cooling but does not have it. Stick a fan to the top of it to make the WAN connection.stabilize. Its easy and cheap to do.

Secondly, get a real router! This is a SME deployment and needs something suitable. You can bridge the 3925 and take all the routing load off of it.

Cuddlesworth

Not a chance in hell that a EPC3925 could route for 15+ devices without crashing constantly. Buy a very high end router and turn the 3925 into bridge mode. Make sure its in a cool room or put a fan on it too.

Maic

Ok. Nice to know. Why on hell the UPC technicians wouldn't say this?? This is a business account... They surely knew that the thing cant handle it.

I will check the temperature. Still the SG300 can be made into a DHCP server ...

Cuddlesworth

Maic wrote: »

Ok. Nice to know. Why on hell the UPC technicians wouldn't say this?? This is a business account... They surely knew that the thing cant handle it.

I will check the temperature. Still the SG300 can be made into a DHCP server ...

The tech would then have to admit that it's not capable of managing a normal house, let alone your needs. Turn it into a bridge so that the only thing it is doing is translating traffic across the coaxial network.