Cisco Switches :: Frequent MSTP Topology Changes On SF-300-08 And SG-300-10?
May 22, 2011
I am trying to configure MSTP on Layer-2 network at work. We have multiple switches connected on Wireless point-to-point links with redundent links.MSTP is configured with multiple regions. All the servers are located in RegionA and other regions are connected to RegionA via multiple links.
There are 3 SG-300-10 switches in RegionA --- SwitchA_1, SwitchA_2 and SwitchA_3.One of the simple regions (RegionB) has a single SF-300-08 switch (SwitchB) connected to SwitchA_2 via port e7 and SwitchA_3 via port e8. Hello Time, Forward Delay and Max Age are at their default values of 2, 15 and 20 respectively. The link between SwitchB (port e7) ---- SwitchA_2 is the primary link with cost 200,000 and the link between SwitchB (port e8) ---- SwitchA_3 is the backup link with cost 500,000.
The log on SwitchB is shows in the table below. As it is seen from the table there are frequent topology changes for very short duration (1-4 seconds) before the topology settles back to the configured one. (Primary link forwarding and secondary link blocking). During this time there have been no link failures reported.Same thing is also observed within RegionA (SwitchA_1, SwitchA_2 and SwitchA_3 are connected to each other).
How to stop these frequent topology changes? The topology changes within RegionA causes a lot of PPPoE sessions to reset and re-establish.Is there any way to find out what triggers these topology changes?
21474646232011-May-24 13:54:15Warning%STP-W-PORTSTATUS: e7 of instance 1: STP status Forwarding21474646242011-May-24 13:54:15Warning%STP-W-PORTSTATUS: e7 of instance 0: STP status Forwarding21474646252011-May-24 13:54:15Warning%STP-W-PORTSTATUS: e8 of instance 1: STP status Blocking21474646262011-May-24 13:54:15Warning%STP-W-PORTSTATUS: e8 of instance 0: STP status Blocking21474646272011-May-24 13:54:13Warning%STP-W-PORTSTATUS: e8 of instance 1: STP status Forwarding21474646282011-May-24 13:54:13Warning%STP-W-PORTSTATUS: e8 of instance 0: STP status Forwarding21474646292011-May-24 13:54:13Warning%STP-W-PORTSTATUS: e7 of instance 1: STP status Blocking21474646302011-May-24 13:54:13Warning%STP-W-PORTSTATUS: e7 of instance 0: STP status Blocking21474646312011-May-24 12:53:22Warning%STP-W-PORTSTATUS: e7 of instance 1: STP status Forwarding21474646322011-May-24 12:53:22Warning%STP-W-PORTSTATUS: e7 of instance 0: STP status Forwarding21474646332011-May-24 12:53:22Warning%STP-W-PORTSTATUS: e8 of instance 1: STP status Blocking21474646342011-May-24 12:53:22Warning%STP-W-PORTSTATUS: e8 of instance 0: STP status
We have 3 WiFi links between 2 buildings, these links carry a main data network, a VOIP network and a CCTV network. Occasionally due to unestablished factors we loose one or other of the links for a short period (5mins to an hour). In order to give some redundancy I opted to use a pair of switches and utilize MSTP to give a low cost solution. I have installed an SF302-08P in one building and an SRW208G in the other building and connected ports 1-3 as trunk ports to the three wifi links on both. Ports 5-7 on both switches are set as access ports and connect to the respective networks within that building. MSTP region is set the same on both switches and the instances and VLANs are the same on both switches. I have set port priority and cost to force the three networks to use their own link until a failure occurs. Then within the MSTP instances I have set the path costs such that CCTV or MAIN failover to VOIP last of all. During testing on the bench using patch cables to simulate the wifi links all went well. Upon installation things got a little more difficult. The VOIP network seems to work well but the CCTV won't pass the video traffic until the SF302-08P is rebooted even though I could connect a PC and login to the CCTV devices from either direction. More serious though is no matter what I do the MAIN network will not pass traffic. The MSTP interface settings show the correct port states with (in the case of MAIN network - MSTP instance 3) Port 1 Alternate, Port 2 Discarding, Port 3 Forwarding and Port 7 Forwarding.However a pcap shows no traffic across the wifi link on VLAN 4 (MAIN) although Layer 1 must be ok as VLAN1 is fine. The only other factor that may be relevent could be the wifi units themselves as the CCTV and VOIP links use an older 2.4GHz bridge while the MAIN link uses a newer 5GHz bridge. The 2.4G units have no knowledge of STP while the 5G units are 802.1d aware but I'm sure I read somewhere that 802.1d devices will cause problems with RTSP or MSTP networks due to the BDPU message format compatability, therefore I left it disabled.
I´ve got a strange problem with the connectivity within a ring topology.There are five switches from the SGE2000 series and one SG200-50.The SG200-50 is the root bridge and RSTP is configured.From the root bridge switch (Switch 5) I can ping Switch 0.But I cannot ping Switch 0 from PC0.
On the other hand I am able to ping all other Switches (1-5) from PC0.In addition to that I can establish a RDP connection from PC0 to Server0.This tells me that there is no general problem with the connection from PC0 to the Switch0.
Right now when I want to configure Switch0 the only way is to connect to Server0 first.But we have to move Server0 and this is why I want to manage Switch0 from PC0 like any other Switch on that network.
I've been taught/under the impression that vlans and stp stay in the access layer to prevent bridging loops and broadcast storms from taking down the whole network. Well I was reading about backbonefast and how it "Enables fast convergence in the networkbackbone or core layer switches after a spanning-tree topology change occurs." Now I thought that from the distribution layer up we use a routing protocol.
we have 3750G stack connecting to H3C switch cluster connecting through two trunk portchannels.and we have MSTP configured since H3C support only MST.MST is configured as below.instance 1 1,168,178,198instance 2 148,158,188,instance 1 LANS are extended to H3C,instance 2 VLANS are local to 3750 stack.,As a new requirement we need to add a another VLAN to this topology.and we are planing to add this VALN to instance 1,can there be any traffic interruptions.
I have RSTP rings consisting of Alcatel 7450's and Foundry FES switches. I want to insert Cisco ASR901's into these rings and have been testing in the lab. It appears that the ASR901's only support MSTP in the EVC configuration. So I would prefer to keep RSTP on the Alcatel and Foundry's and enable MSTP on only the ASR901's.
Topology is:7450-2 <=> Foundry-2 <=> ASR901-2 <=> Foundry-1 <=> ASR901-1<=> 7450-1 with a VPLS between the 7450's.
If I enable MSTP in the Foundry's, Alcatel and ASR901 everything works fine. If I keep RSTP on the Foundries and 7450's, then STP also works, with the exception of a Foundry-2 switch running RSTP, that is located between 2 ASR901's running MSTP. This switch does not seem to interact with the other switches (i.e. thinks it is the root bridge).Since there are mulitple MSTP boundary's, do the ASR901's need to be in different IST's/instances?
I am just browsing and looking for a solution to converge my multi-vendor switched network and bring some redundancy to it as recently we managed to get a redundant links. I have a need to change core switch to Cat3750G, which has Per-V LAN-RSTP+ on board, but tests have shown that it won't be compatible with some other proprietary per-V LAN RSTP solution other vendor's switches use currently.
So, I thought maybe standard-based MSTP design might do the trick. I've made some tests and got some weird and unstable switching result. I have two topology rings with a core switch in the center. Every ring has about 10 switches, so practically network diameter may vary from 5 switches (when spanning-tree converges in the center and I have a blocking port somewhere int the middle of the ring) to about 10-11 switches (if a I have link failure on any of ports right at the core switch). I disconnected one port from core switch to eliminate a possible switching loop while I will be configuring new MSTP design. Then I started enabling MSTP on all the switches staring from core Cat3750G to MSTP, one by one, placing all switches to the same MSTP region, and placing all V LAN's to default MSTI0(CIST) cause I don't need to organize any separate MSTP instances for every V LAN or for group of V LAN s. When I turned MSTP on on 7th or 8th switch in the chain (cause I had a physical chain when I disconnected one port out of redundant ring) I got all switches "flapping", storming and flooding the network with broadcasts. Even when I had one redundant port disabled.
I have no idea what I am doing wrong. I noticed that Cat3750G has an option that defines a possible network diameter which actually automatically changes some hello, max age etc. attributes according to diameter specified. When I defined a maximum network diameter of 7, if didn't change anything: I still have hello timer of 2 sec etc. I've been wondering if the maximum network diameter has something more than just a "variable" to fine tune hello timers etc? Maybe I won't be able to use MSTP in my network which might have diameter more that 7 switches. Or maybe it was a mistake of placing all the switches to the same region and all the v LAN s to the default MSTI0 (CIST) and I should configure one MSTI per V LAN or per some group of V LANs and subdivide my switches to few MSTP regions?
On a pair of my CISCO7609-s (engine:sup720-3B IOS Version:12.2(33)SRD4),some interfaces is configured as routing interface but also them are attend MSTP caculation and i really caught BPDU packet go out from these ports. [code]
I am having issues with frequent bgp flaps on the Cisco 7200 series router from past 1 week. I have raised a ticket with ISP but couldn't get any resolution from them as the flap is for about 2min.When ever we see BGP flap, we are not able to ping the remote end IP, Also at that point we drops on the interface connected to ISP.
I have a Cisco 1841 router which stops functioning sporadically. You have to manually go do hard reboot on the router before it starts working properly.When it goes down, you cannot ping its internal interface (from the LAN side) not its public interface, it seems to go down quite regularly.Where do i start to diagnose, is it hardware failure, or config issue. Nothing has changed as far a the config goes lately.
At our house we have Fast Access DSL through ATT. We are getting very frequent disconnects and lags. We have multiple devices running off of a single DSL modem/router. It has wireless and wired connections available. Our wireless devices disconnect as frequent as our wired devices do. We have called ATT many times. They have had us replace the DSL filters and did a line test outside our house which came back clear. However, when they run a line test while I am on the phone with them, they say they detect multiple errors on the line. We have replaced our DSL modem with a new one as well. It is a NETGEAR VersaLink Four Port Ethernet Wireless Gateway, Software VER:06.04.12. The self-diagnostics on the Modem come back clean with no problems detected. We get static on our phone line frequently as well.
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In the technician readout part of my modem I also see this:
1Manufacturer NETGEAR 2Vendor ID b5004946544e449c 3Model NumberB90-755025-15
I have Cisco 7613 on my edge(MPLS Backbone). CPU utilization is shooting to 100% at frequent intervals. When I tell vendors managing device they tell that it is happening due to one of my server(connected on Fast ethernet port of 100Mbps) generating heavy traffic. My questions are:
1. Can a router of 720Gbps capability be choked due to traffic generated by 100Mbps link?
2. Interrupt CPU process utilization is well below 10% at the said time. BGP router process consumes most of the CPU. Does this means that server in question is generating too many routing updates?
3. Is there any way that I can limit routing updates on a particular link?
4. how to check which link is causing more CPU utilization.
I have multiple RVS4000 in a VPN ipsec Site to site to a ASA5505. The connection is fine most of the time.But the VPN connection randomly drops, not all the devices at once but they all do at a different time.
I just got Charter cable internet and decided to purchase my own cable modem instead of paying 5 dollars a month to rent one. I got a D-Link DCM-201. I know it is a little old but it was brand new/unused so I figured it would work out well. Ever since we got it hooked up every few hours we lose internet connectivity. The power, cable, and status lights are solid green and the Ethernet light is blinking green. The only fix I have found for this is to power cycle the modem. The problem is this happens about once every 4 hours...having to reset the router every few hours is making having cable internet a much more painful experience than it should be.
I keep losing connections to the internet and getting a couple of different messages that the Gateway IP address is invalid. There are times it happens every few minutes and other times I can go for a couple of days without it. Also, we have to have satellite internet which has such an inconsistent speed. Is it the internet speed inconsistency or the 4 year old Belkin N Router?OK, so I tried to copy the information from the CMD window, but I can't get it to work. After I got the information and right clicked and clicked "select all" then what. I couldn't copy it. I can't find my way back to the instructions.
The internet connects fine, but every couple of minutes it will disconnect for a couple of seconds. It's not a big deal when browsing, but it's disastrous when downloading big files or playing online games.What I've tried so far:
-Resetting the modem. No change. -Reconnecting the modem/router completely. No change. -Replacing the main splitter. Slight change, but problem came back eventually. --Original problem came with the tech's 2 way 5-1002 mhz spliiter. --I tried replacing it with a 3 way 5-1000 one. The modem on 7db and cable on 7db. It worked fine for a couple of days. --Problem comes back today. Moving the modem to any of the 3 outputs doesn't fix anything. Moving it to 3.5db actually causes a short timeout every minute when I try to ping yahoo (as a test). --I've also tried a 2 way 5-900 mhz splitter. It was the worse one of all.
Other info:The internet went down to the entire block at the start of the year. No one knew this of back then so we made a call to comcast, and they scheduled for a tech. A couple days later, we decide to get a new modem from the comcast center just to make sure it wasn't our modem. Some problems with activation prevents us from knowing if it was. We get back online somehow the next day, which is also the same time the tech came. He decides our numbers are weird and adds in a splitter for the internet and tv (which leads into another splitter for each room), and an amplifier for the tv. In the middle of this, another tech stops by and tells us the entire block was down and he said he fixed it now, he doesn't stay long. The first tech finishes installing everything and leaves. All is fine for a couple of days, until a week later and we start experiencing frequent disconnects. We've tried calling comcast again, but they say the connection is fine on their end and the problem is with our router. When I ping the router and the modem directly, there are no dropped connections. It's only when I try to ping anything on the internet when the problem pops up.
As indicated in the subject, wireless users are finding that it is either unattachable (shows up in the list but fails to attach) or if you manage to authenticate and get in, it's painfully slow or simply drops out. Security is WPA-PSK. Only noticed the issue after a couple of Windows 8 laptops came into the household, but the problem still seems to be there when they are off so not sure if they are connected in some way or not. Updated to the latest firmware - no change. Wired connections are fine and when it's initially restarted, so is the wireless, seems to happen sometime after wireless services are restarted. Only the one Wireless SSID, nothing fancy, max users around 5, all on laptops or the odd pad. I changed channels done narrow wide etc, (using mixed mode - some Wireless N laptops some Wireless B/G. Nothing seems to make any difference. No log entries until the Wireless system is restarted, doesn't require a reboot of the router, just a SUBMIT of the existing wireless settings to force it to restart.
We recently converted autonomous 1131APs to LWAP. We have some 802.11b clients that were associated to these APs and they worked fine. Ever since we converted them to LWAP, the clients frequently disassociate and it causes alarms on these wireless clients which are used as monitors.
WCS shows the client disassociation and re-association and it says the roam reason as "unspecified". It associates to the same AP and keeps the same DHCP client address etc. I tried setting a static IP on the client but that did not work. We verified the PSK settings and they all match between the clients and the controller. [code]
- Small Home-Office network based on a Cisco WRV210 VPN Router connected to another WRV210 in a remote location. - The WRV210 provides 2 WAP-protected SSIDs, one for the office network and one for visitors - Wireless channel is set 5 channels away of the closest networks (using inSSIDer) - There are about 12 wireless devices, 4 connected to the office network the rest to visitors. Not all devices are connected at the time of failure. All wireless devices use DHCP which is set to last 1 day and provide 100 IPs. - The wireless devices are 1 desktop, 3 notebooks (all clean), iPads, iTouch and Nook. - The failure symptom is that almost daily, and most likely around the same time, no wireless device can connect to any of the SSIDs unless the router is power-cycled. During the failures, which we have witnessed first hand, there are no apparent reasons: no new SSIDs, now SSID in close range on the same channels, nothing we can easily observed in the network in terms of connections or unusual activity. - A weirdo also presented by the WRV210 was that its web pages were shown erratically. That was corrected by downgrading the firmware from the latest to previous version.
We have used a loaner Linksys router WRT54GC with only the visitor Network on it and even though the situation is not as frequent, it has happened already a couple of times.The WRV210 is out of warranty and discontinued, so we get no support from Cisco that is worth paying for.
I have a new deployment with a Cisco 5508-50 controller running 7.0.220.0 code and 35 AIR-LAP1262N-A-K9 access points. Current legacy clients have trouble connecting and after connecting they may or may not drop off and have trouble connecting again.
I have problem with RV120W router, device reboots very often ( up to 3-4 times during working day ), firmware is up to date ( 1.0.4.10 ), last week I decided to use "restore the factory defaults" unfortunately problem still exists.
Router is working in small office, there are 3 PC and 3 VOIP phones ( connected via LAN ) and 1-2 devices connected via wireless ( smartphones )
I've tried to view some logs but unfortunately no luck, can see some errors/warnings in dashboard ( see attached picture ) but cannot see more details ( log configuration wrong ? )
Additionally sometime I can see that CPU utilization is 100%
I am running XP pro. I have checked thoroughly for viruses/malware/etc. and everything appears to be clean. I have up to date drivers for NIC's, have cleared all temp data, done basically everything that the first tier Time Warner Cable(my ISP) tech support people will tell you to do as they read from that frustrating script we're all too familiar with and have had to deal with time and time before, including resetting modem and router, bypassing router, etc. etc. et bloody cetera.Ran several pings to a variety of servers and noticed ping spikes every 10or so seconds into the 300-600 range from an average of about 20-30ms.
I've recently bought an Actiontec V1000H gateway from Telus because my previous gateway burnt out. It seemed to work fine at first, but then I started getting disconnected at random. The only way I have found to fix this issue temporarily is to ipconfig /release and /renew.
I have moved into an apartment with 4 friends of mine. We all own HP 6515b Laptop running Windows 7. We connect to the internet through a wireless router. Our connection's name is LINKSYS and is WEP.Once i have connected to the internet, it will continue to work fine for a while. After some random time, it will disconnect.(The computer stays connected to the wireless modem, but computer shows NO INTERNET CONNECTIVITY (in bottom-right taskbar))Then in 5-6 seconds, it will start working again... The only change that is visible is that the exclamation mark on network disappears. The computer remains connected to router for this whole time. Initially we thought it was a problem of our ISP. But later we found out that at a time not all users face disconnection.So at a particular time, it is possible that only I cannot open webpages.
I am running Windows 7, Time Warner Cable is my ISP, I am using a Netgear wireless router, and a netgear wireless card to access the signal
The problem started a week ago. While playing online video games (Battlefield 2), I will get a message on my screen telling me theres a problem with my connection. Sometimes it will only freeze up for 5-7 seconds, and sometimes it is up long enough to make me lose connection to the server.I am not having ping problems, the server is not kicking me for that.All background programs are closed, ive tried restarting everything I have thats related to internet and my computer.
We have two 3845 routers set up using HSRP at two locations (4 routers total) connecting inside to a pair of ASA 5520 (Active/Passive failover) on each side. These links are used for internet access and they work great under normal operating conditions - they fail over and fail back without issue. How ever, two weeks ago our operations guys started a new data replication procedure going across these links via an IPSec tunnel created between the ASAs. This seems to have created a situation where the IP SLA tracking is not be able to receive the ping back from the upstream router on the originating side. [code]
I have our SIEM set up to notify me whenever the router logs a State change and I got about 10 a day
i have an issue with the lms 4.2 Topology Data Collection. After installation the Topology Data Collection was running normaly, but since first server reload the Topo Data Collect under Inventory > Dashboards > Device Status > Collection Summary is "frozen".Is there any option to stop this process elsewhere? I cannot find anything under jobs in running state or so. Clicking on Schedule only give me the option to start data collection, but lms always returns that the process is running.
1)i have problem in LMS 4.2 , he shows most devices not connected to topology sitting lonly even though the have cdp enable , how to force these to join the topology
2)why some devices are shown unreachable , even though i can ping them from lms server and gets reply, also they have community and cdp configured
On a LMS 4.0.1 :I want to know what is the right way to change the telnet program on the campus mgr map (topology services map), when right-clicking a device icon and selecting telnet.I would like to use a tool of mine, and not to launch a telnet command from the IE browser.I changed the default telnet of Windows in the registry, but the program is still launched as a telnet URL in the browser and this is not what I would like to do.
The regular problem with the LMS topology and WAN Links when you see the branches are disconnected from the HQ BUT in my case the branches are already connected via Layer2 links but unfortunately some intermediate layer2 modem/switch exist in some branches which prevent CDP discovery but you will find both HQ and branch router in the same subnet .
have ether-channel across 2 switches?i am new in cisco LMS . now i am in client site installing cisco LMS 4.1 in UCS server-rack version. we did it well for the installation, and the LMS working properly until i cannot open topology service.
I have a customer who wants to disable cdp on all switches for securtity reasons. The same customer has also LMS 4.0 installed.
When disabling cdp, does it affect the topology services on LMS? Can you still see the topology tab on device manager or the topology map of the entire network?
