Cisco Switching/Routing :: 1841 Router - CPU Suddenly Hit 99%
Oct 7, 2012
I've never had a router's CPU suddenly hit 99% and just stay like it for hours even after a reboot. This router really does nothing with regards to CPU, I'm looking at it's CPU history (via SolarWinds Orion NPM software that we use) and it is arounf 1-3% all the time for the past 2 years.
I did a show debugigng and it seems no debugging is running
We have a Cisco 1841 router that requires 2 levels of access, at the moment we have network admins logging in with a single username via SSH and with privilege 15 but we also need our helpdesk to login to run certain commands but not chaneg anything
We currently have a Cisco 1841 router with version 12.4(1c) of IOS using image c1841-ipbase-mz.124-1c.bin. Our goal is to make it so our router can fully support IPv6. The current IOS version cannot. I've seen a site that seems to indicate 12.4T does support with IP Base image but recently had Cisco tell me with the latest IOS release 15.1.4.M4 that I have to use either the "Advanced Enterprise Services" or "Advanced IP Services" image. Did Cisco just remove IPv6 from IPBase in later IOS releases?
Also I've seen conflicting specs on the max amount of Flash and DRAM the router can support. The following link shows that 384MB is the max for DRAM and 128MB max for flash. We're looking to upgrade ours from 128MB and 32MB respectively but as mentioned I've seen it where higher amounts are supported. In fact we bought a backup 1841 to have and it has a 256MB Flash card in it.URL
Last but not least. Where can I find a straightforward documention of this situation where we may have to upgrade our Flash and DRAM and then upgrading the IOS?
I have got a l2 link of 512 kbps from two different ISP. I want to aggegrate the bandwidth of this connection so that I can feel like having 1 mbps connection. I am not actually talking about load balancing, but bandwidth/link aggegration. Can we have the solution of failover with different vlan from different isp ? Can we be able to make the link as a single link.
I'm at a FOX affiliate TV station, and in order to connect our EAS Device to the internet & Fox Splicer, I need to setup a Statio NAT, so we picked up an 1841 on eBay.
I've done a little configuration in HyperTerminal.
I've done these ip addresses:
FE0/0 10.1.10.13 this is the subnet our EAS device is on FE0/1 10.110.81.174 this is the subnet of the Fox Splicer.
I need to have NAT translate 10.1.10.11 to 10.110.81.170 and I also need to set a route for 10.110.81.0/24 pointing to 10.110.81.161
due to upcoming changes to our network I'd like to be able to pass vlans across the FE ports of a Cisco 1841 router.1 port would go to a managed switch and then to local devices on different VLANs.the 2nd port would go upstream to a Cisco 3825 at a different location which would then connect to the internet.due to monitoring behind the Cisco3825 we would like all NAT to occur on the 3825.
what I would like to happen is this example device connected to port 7 on managed switch gets an IP (10.0.7.10) from the Cisco 1841 in VLAN 7 (10.0.7.0/24).traffic from that device goes to the switch, then in f0/1 on the 1841 and out f0/0 still with the same IP info, no NAT occuring.traffic is received on the 3825 port 0/1 and then NAT occurs and out port 0/0 to the internet.
I have 10Mbps internet speed connected to ciusco router 1841 that has 2 internal NICs. One NIC has a full 10Mbps download speed and the 2nd NIC is currently limited to 1Mbps download speed. I want to change the download speed of the 2nd NIC to 4Mbps? How do I do this on a cisco 1841 Router?
The issue is occuring on our local LAN where my ARP requests are being modified after a period of time by the router for one host. I'm finding that the host will work fine with the correct MAC IP pairing for a period of time and then about 15-30 minutes later, the arp table is changing so the associated mac/IP address is now the mac address of the router interface.
The FastEthernet 0/1 port has no ip proxy-arp enabled and is set with ip nat inside.This only started happening after restarting the router, however the running config was saved as the startup config prior to the restart.I've tried hard-coding the entry with the command arp 10.15.4.190 c82a.1459.0579 ARPA however that is not working as expected.
The device is an 1841 ISR with the advanced IP Services bundle loaded. Is there some way that the router is viewing my host (provides DNS, Directory Services) as a intrustion attempt and somehow rejecting the packets?
We have a setup of a firewall in between my Cisco 1841 router and Switch.
Cisco Router --> Meraki Firewall--> Switch
Client VPN is configured on the Meraki Firewall but then for the outside users to client vpn in to the network, I have to port forward or open the ports 500 and 4500 to the IP address of the Meraki Firewall 192.168.1.90. [code]
We have a 1841 Cisco router for one of our remote sites and we have the GRE over IPSec tunnel on it (with our datacenter router) for the connectivity. The LAN facing interface becomes UP/Down (status 'UP', Protocol 'Down'). When I login the router and 'shut' and then 'no shut' the interface, the interface becomes UP and everything starts to work. Traffic starts to flow across it. But after some time, some hours or sometimes some days, the interface is again back to up/down status. The router is connected to a non-Cisco switch. I do see some CRC's increasing very slowly, but apart from that there seems nothing wrong with the interface in sho int fas0/0 command:
! RTR01#sho int fas0/0 FastEthernet0/0 is up, line protocol is down Hardware is Gt96k FE, address is 0026.cb91.ee48 (bia 0026.cb91.ee48)
I want to know is it possible to check Internet speed directly in the cisco router thru any command or activating any service in the cisco router?.As it is seen most of the times internet speed offer by ISP is different as compared to clients.and Clients most oftenly not satisfied with internet speed The problem is that our ISP has given us 100MB leaased line.But when we deployed in production network the speed is same as DSL.We have reported this issue to ISP they then carried out Iperf test by connecting laptop directly with the ISP router.They have tested the speed and it shows about 94-96 Mbps and argu that it is up to the mark and there is problem at your side(i.e our internal network).Now our internal network has cisco 1841 router connected directly to ISP 3825 cisco router.Our router has minimum configuration as required to pass traffic out and in.Our internal 1841 router is connected to switch to which different clients are connected.We have performed some online tests using different speed checking websites and also perform real time tests by uploading and downloading files.The speed is much low as compared to 100Mbps and it is nearly or slightly higher then as DSL connection. how can we check internet speed in the specified scenario?Is there any command or service available in cisco router to check internet speed as we want to check ISP connection speed directly thru 1841 router?what about authenticity of online speed checking websites?Any specialize software/tool you recommend to check Internet speed in specified scenario?
I've moved a Cisco 887 router from a site where it was used to dial up on an ADSL line to a new site where we have a EFM circuit which terminates at a Cisco 1841 router managed by our ISP. I therefore need to re-configure our 887 router to work as a conduit from our servers back to the Cisco 1841 as its gateway.
I have asked from our ISP and they told me that i need to configure the 887 to use IP address 176.35.140.65 255.255.255.248 and its gateway should be 176.35.140.70. That's great advice in theory but I don't know how to configure this correctly
Our internal network is using subnet 192.168.42.XX which will need to be retained for local devices.
I am using Solawinds syslog and trying to get our Cisco routers send syslogs to our syslog server. I followed the procedure on Configuring Cisco Devices to Use a Syslog Server from [URL] Our Cisco swtches are all sending syslog messages but not the routers. I compared the config with our access switches but can't seem to find the problem:
I am just setting up a simple scenario with a 1841. Server @ 172.31.1.1 cannot ping 172.31.0.254 or 172.31.0.105. It can ping 172.31.1.250. The router can, on the other hand, ping devices on both networks. This is just for testing routing theory so I don't know why hosts on either side of the network cannot ping each other.
I am only using the FastEthernet interfaces on Router 1841.
The router 1841 is connected directly to the layer switch. the network diagram is below:
Office A --> Switch (L3) --> Router 1841 --> Internet --> Office B
However, when I transfer the file from Office A to office B, the speed very slow ( only around 40 kb/second), and there are an input error and CRC error:
Cisco-R1841#sh interfaces FA0/1 FastEthernet0/1 is up, line protocol is up Hardware is Gt96k FE, address is 0019.e02f.03dd (bia 0019.e02f.03dd)
I'm just getting started with cisco kit so you will have to bare with me.I have a cisco 1841.i have a very wierd issue of routing...i cannot ping and browse through this.
I have two VLANs - 10 and 20. 2 DHCP pools are configured on 2 1841's interfaces - 192.168.1.0 /25 and 192.168.1.128/26 with default router sitting on 192.168.1.1 and 192.168.1.129 respectively. No issues with obtaining IP address from any of those pools.Laptop connects to L3 3550 switch (switchport access vlan 10), which, in turn, connects to 1841 router through trunk (with VLANs 10 and 20 allowed).3550 is connected to 2960 through trunk with VLANs 10 and 20 allowed.Wireless router is connected to 2960.I can successfully ping my wireless router and outside world from 1841 from fa0/1 interface, but not from fa0/1.10 or fa0/1.20 sub-interfaces - all packets got dropped. My laptop can obtain IP from both pools (depending on port I connect it to), but can't ping my wireless router and anything beyond it.
I have a Cisco 1841 router at home with version 12.4(13r)T advanced ip services. The setup is extremely simple:
1) PPPOE dialer to my service provider over ADSL 2) Nat overload on the dialer interface. 3) 2 V LAN s one for home network (wired) and one for wireless both v LAN's are connected through interface v LAN s respectively.
My problem is when I configure static NAT to map RDP or any other protocol to inside hosts this does n`t work. " ip nat source static tcp 192.168.20.3 2222 interface Dialer1 2222 ip nat source static tcp 192.168.20.3 3389 xx.xx.xx.xx 3389 extendable ip nat inside source list 20 interface Dialer1 overload "
When I open wire shark and sniff the traffic on home computer which is the one I`m trying to reach I can't see any traffic. And While performing Nat debugging I am also not able to see traffic going to that port (for example 3389).
I've got an 1841 router and am using NAT to expose certain IPs and ports to the outside world so that external users can see internal resources (namely, web sites). However, I can't seem to get it running such that I can visit the external IP address from inside the network and get the router to turn the request around so that it is redirected back inside the network. Shouldn't this be possible? Our previous router (a non-Cisco) was able to do this, but I can't seem to get the new one to do it.
A couple of key config lines: interface FastEthernet0/0 ip address a.b.c.178 255.255.255.240
I tried to connect a 1841 to a Linksys with a static route. I am able to ping from a computer in the 1841 to a computer in the linksys network, but I can't ping from a computer in the Linksys network to a computer in the 1841 network?
I guess i am just getting old and forgot how this works, or i have an IOS load with an undocumented feature in it.A customer of ours wishes to have their exchange server appear to the outside world on a seperate IP address as their public pool address is.in the past this has not been an issue, however in the current configuration we are unable to get the source address to appear per the NAT statement it always sources on the overloaded IP. below is the relevant NAT config, am i missing something, or have i hit a IOS feature? [code] There is a 45% chance i have forgotten everything i learned on the NOC desk and a 50% chance that it is somethine really stupid and 5% IOS is broken
I want to SSH into a Cisco 1841 router and depending on the suffix added to the SSH (i.e ssh myrouter.myroute.com 2002), would like it to forward this request to a terminal server.Can this be done? If so, how does one accomplish this? I have done something similar with RDP but I was not sure about SSH.
What is the command to shutdown a cisco 1841 (say, to add a module)? I know how to reload / reboot, but does not seem to find any command with an obvious name.
I have an 1841 running Advanced Enterprise Services 12.4(22)T3 that is functioning as a DHCP server and DNS server. What I am trying to figure out how to do is have the DNS service respond to queries about the clients of the dhcp service. I have successfully enabled it as a caching server for other requests, like "google.com" and "cisco.com", but what about the hosts on the local LAN?
As an example, let's say a Windows computer connects to the network with the hostname "computer" and receives an IP address from the 1841 with the domain name "test.net". I would like the 1841 to serve DNS queries for "computer.test.net" with the IP address that it assigned.
we've to configure our router 1841 to use both 2 interface Fe for two different vlan (also the second has to go on internet).
Actually we have int Fe0/0 configured with an ip address 192.168.1.1 for lan1 192.168.1.0/24 and we will use the second int Fe0/1 with another ip address like 192.168.2.1 for lan2 192.168.2.0/24.
We upgrade our Internet service in our India office which required a new router. The local vendor suggested an 1841, so that is what we have. It has two fastethernet ports on it.
The ISP (Airtel) provided the following IP address information:
Public WAN IP : 122.181.23.200/30 WAN IP : 122.181.23.202SUBNET MASK : 255.255.255.252GATEWAY : 122.181.23.201Pri DNS : 125.22.47.125Sec DNS : 202.56.250.5
I have a cisco 1841 running on a 10Mbps Metro-E connection. I recently signed an agreement for a 100Mbps Metro-E. I am wondering if I will need to purchase a new router to support this new connection or will my 1841 be able to handle the traffic.
I am trying to config the following setup in the Cisco 1841. Able to ping the IPs of Vlan1(FE0/0/1), Vlan2 (FE0/0/1) and FE0/1 IPs from corresponding networks. But packets are not flowing to other side.