Questions tagged [cisco]
The major provider of networking equipment. This is a generic tag to be used when no more specific tags are available. See the list of tags in Help Center Tag page.
3,759
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OSPF LSA Refresh Time
Is there a Cisco command that would allow one to modify the default value of 1800 seconds (30 min) for the OSPF LSA refresh rate?
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4
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Embedded routers vs. software routers in the datacentre
I've been looking for a new 'core' router to put in our new rack which is colo'd at a nearby datacentre. What I've come across is the usual Cisco/Juniper/Brocade lineup, with the usual unattractive ...
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ISR routers - difference between routed and switched ports
On a Cisco ISR router - would you say there are any benefits from purchasing an HWIC or EHWIC to connect to the next set of switches within the branch network?
For instance. Lets say Gig0/0 and Gig0/...
- 3,052
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Output Drops on Serial interface: Better queueing or Output queue size?
On Internet edge routers speaking eBGP to multiple carriers and iBGP to one another, all interfaces on the LAN and WAN side are GE except for one Serial full-DS3 (~45Mbps) on each router. Although I ...
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How do I obtain access to buy from Cisco directly? [closed]
I'm fairly new to the purchasing and licensing of new Cisco equipment. In the past, I have used eBay for all of my Cisco shopping needs. I know that I can purchase new equipment and licenses from ...
- 29.8k
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1
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What is the difference between a VRF and GRF? (cisco)
I've heard about VRF's and GRF's, but was is the difference between those 2? (cisco)
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CDP not available to be enabled on ME3400 port
We have a ME3400 that we want to enable CDP on but there is no cdp option. Why is it not available?
switch(config)#int gi0/1
switch(config-if)#cdp ?
% Unrecognized command
CDP is enabled globally.
...
- 2,535
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1
answer
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AP's at remote faciltiy will not join local controller
I currently have a WLC 4404 running 7.0.240.0. Management Interface IP is 10.128.55.10. AP-management interface is 10.128.55.15. Remote facility (facility A) has a VLAN created for wireless (455) ...
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How to throttle speed for a particular computer with high activity?
We're in an office environment of about 50 people. A few departments send emails with large attachments extensively and doing so clogs up the WAN connection (10Mbps).
I'm upgrading the networking ...
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4
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OSPF LSA Performance Tuning
Does it make more sense to modify the 1800 second refresh rate, pacing timers, or all of the above in terms of network stability/best practices/etc to achieve quicker LSA maintenance?
I am dealing ...
- 9,421
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3
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Default-network and default-gateway
When would you choose to use the ip default-network command instead of the ip default-gateway command?
- 2,884
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2
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What are the best Cisco 6500 Ethernet modules for iSCSI?
I have a SAN environment built on FC (Fibre Channel), which is a standalone network from the rest of the DC Ethernet network, and have only Cisco 6509s with Sup720s available for this project.
Most ...
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2
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Cisco: No autostate on GigabitEthernet interfaces, any alternative? (not working)
I recently tried the command "no autostate" on a GigabitEthernet interface (on a newer router) and this didn't work anymore, does anyone know why this is occuring? This use to work on FastEthernet ...
- 2,363
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1
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Cisco config example for Policy Based Routing
I find my self in a situation I was in not too long ago, but I can't
remember how I resolved it :)
The Scenario
I have a Cisco IOS router with a LAN interface (fa0/0) and a WAN
interface (fa0/1), ...
- 2,363
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5
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How can I speed up CLI typing in Cisco IOS using shortcuts?
I know we can use auto-completion (tab key) and abbreviated commands (such as sh ip int bri) to speed up typing.
However, I'm still not satisfied with typing crypting chains such as sh ip dh sn bi | ...
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3
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Why does "show adjacency" take so long to run?
Why does the "show adjacency" command take so long to run (in the order of minutes) on Cisco IOS Software, 7200 Software (C7200P-SPSERVICESK9-M), Version 12.4(4)XD5, RELEASE SOFTWARE (fc1)? The ...
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How can I disable SIP on IOS 12.x
How would I disable SIP on an Cisco router running IOS 12.x?
- 2,363
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2
answers
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Is migrating to VRF or rolling-back an easy proposition?
If VRF is implemented for routing table separation such as having an overlay network for a guest network that doesn't mix with regular LAN routing, is migrating to it easily done on Cisco switches (...
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1
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What's the difference between CRS-1 and CRS-3
What are the differences between the CRS-1 and CRS-3 platforms? I know the CRS-3 is the upgrade to CRS-1.
Do I need a new chassis to upgrade to CRS-3? Or is a CRS-1 chassis upgradable to a CRS-3 ...
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3
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How to apply configuration after replacing Routing Engine(RE) for CISCO7609-S?
Senario:
I have the backup configuration file. But I don't any USB drive or compact flash card. After replacing the Routing Engine, I tried to copy/paste the configs (around 12k lines) from the ...
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2
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DSCP trust boundary
I have performed some analysis and noticed that traffic coming in from the Internet contains a myriad of DSCP values. This traffic competes for voice and video resources on the internal network.
How ...
- 2,435
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1
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How can I log authentication errors in 3G routers?
What command (debug) can I use to see authentication errors on a cisco 3G router specifically for the 3G connection?
- 9,421
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1
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Etherchannel connections between Cisco and Nortel switches
I need to create a 6 port static Etherchannel link between a stack of 3 Cisco 3850's and a Nortel 8310. Can someone provided a basic config for the Nortel side. I have little experience with the ...
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Can FlexConnect ACLs be combined with Local mode ACLs on the same Cisco WLC WLAN?
There's a limitation (stated below in Cisco's documentation) that FlexConnect ACLs in Cisco WLC cannot be combined in the same WLAN with local mode ACLs. The GUI allows the entry of a local mode ACL ...
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3
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QoS at the edge of branch
I have a question about QoS design in branch. The main place to deploy qos in branch - edge between edge router and ISP. At this edge we have voice traffic to SIP provider, copr. external email and ...
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Cisco Nexus 5000 grounding
I have heard that all 10G switches must be grounded. We have two Cisco Nexus 5000 running for years without any grounding, but I am worried about possible outages caused by ESD. Nexus 5000 has system ...
- 29.8k
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What is the benefit of a Cisco "top of rack" design?
Aside from the obvious cabling mess you avoid (which I know for us as network engineers is great, but hard to use as an excuse when reasoning with someone who sees no point in it), what do you gain ...
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5
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Can netflow be left on all the time?
One of my colleagues and I have gotten into a debate about netflow. He's an old Cisco hand and I've recently joined the cisco ops team after working on Juniper for a few years. The debate is whether ...
- 6,104
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Cisco Catalyst cluster heartbeat switch issue - increasing input errors
PROBLEM:
The servers in two clusters keep losing heartbeat connectivity with each other thus causing database outages. Outages are brief but disruptive.
SETUP:
There are two clusters of three ...
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Communication Manager Business Edition 6000 - understanding bundle equipment
I have a Cisco Communication Manager Business Edition 6000 specifications. Can you explain some facts about it.
Link to specification
According to this, we have BE6K-ST-BDL-K9 (#1) and it contans:
1....
- 29.8k
3
votes
1
answer
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Source of Cisco NBAR dropped traffic
I recently implemented Cisco NBAR at a remote sites, edge router.
to filter and drop P2P traffic.
I see the dropped traffic by typing "show policy-map interface XXX"
how can i find the source of the ...
- 29.8k
6
votes
1
answer
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After a memory upgrade of my Cisco WAAS, why is the connection limit still the same, how can I raise it?
We use Cisco WAAS appliances for WAN optimization. With increasing traffic, we noticed that the connection limit was frequently reached. In case of our WAVE-574-K9 with 3 GB RAM, there was a limit of ...
- 3,374
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3
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Management network. Best practises: big VLAN or routed interfaces
We are going to deploy a campus network with approximately 50 switches (Core, Agg, Access). Some of them will be L2 (20), and others will be L3 (30). We are thinking about how to manage these devices:
...
- 27.2k
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Which is the Preferred location of an IPS within a network? [closed]
In the context of protecting a campus network, which is the Preferred location of an IPS within a network?
Within an ISR router
IPS as a separate device
Within ASA
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catalyst 3750x - jumbo frames on svi
I've encountered a problem on a cisco ws-c3750x-48ts-s where jumbo-frames won't cross a trunk-connection between a vwmare esx-host and the switch.
The access ports in the same vlan don't experience ...
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What is the NO PAYLOAD ENCRYPTION version of the IOS software?
When looking at the downloads available on the Cisco site, they have a regular version of the file and a NO PAYLOAD ENCRYPTION version. What is the difference? And why would one choose one over the ...
- 27.2k
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2
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How to use "Pattern Recall" pattern matching in Regex
I'd like to match the 0's in this output, specifically using "Pattern Recall" feature mentioned in Cisco documentation.
The pattern is:
Gi4/3 0 0 0 ...
CommunityBot
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How are two "ip helper-address" statements handled?
I've discovered a subnet with two "ip helper-address" statements. This is not our normal configuration.
interface Vlan300
ip address 10.1.3.2 255.255.255.0
ip helper-address 10.2.1.10
ip helper-...
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Monitor specific traffic type on a Cisco router
Is it possible to monitor a specific traffic type going through a cisco router? (like monitoring via wireshark)
Ex: I want to monitor http traffic specifically that is passing through a router. (or ...
CommunityBot
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3
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How do you know if a Cisco switch is handling traffic well?
I have just read Jeremy's question about 2960-S and iSCSI traffic handling, which drove me to ask this question: We all have lots of switches deployed in distinct infrastructures, how can you know ...
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Cisco: prevent vlan's of communicating with eachother on cisco router (ACL alternative)
Setup: Cisco router with multiple VLAN's configured on it.
How can you prevent 2 VLAN's communicating with eachother? Normally I would do this with ACL's like this:
access-list 102 deny ip 1.1.1.0 0....
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Cisco 1921 security features in the default bundle
Bought a Cisco 1921 router without any additional modules. This is the first time I'm using a non-home router. What security features should I enable so that users are relatively safe when using the ...
- 31.7k
9
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ASA Netflow support
Cisco ASAs support a version of netflow called NetFlow Secure Event Logging (NSEL). Is special support for the protocol required on the collectors to view the flows? Is the protocol compatible with ...
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Etherchannel on 6509 (VSS) with interfaces from different type of modules supported?
We currently have 1 10GB Multi-Chassis etherchannel Between 2x 6509 (VSS) and 2x 3750-E (Stack).
On the 6509 the etherchannel interface members currently run on the supervisor module VS-S720-10G.
We ...
- 1,793
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3
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Oversubscription in cisco 6500
What is oversubscription?When selecting a 16 port 10 gig blade for cisco 6500 , it says oversubscription as 4:1. What will happen if I populate all 16 ports, will some ports be blocking or dropping ...
- 29.8k
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Cisco active/standby FWSM pair went active/active after switch upgrade
PROBLEM:
Both FWSM in our core switches went active/active and protected subnets have partial accessibility.
SETUP:
We have 2 x Cisco Catalyst 6509 switches running IOS version 12.2(18).
Each ...
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5
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In a multi-tenant environment what should be done to make your switchports silent on Cisco and Juniper switches?
For example preventing it from sending arp, stp, etc and to reveal as little as possible about the rest of the network.
Example use case would be connecting to a peering exchange.
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Wireless Probe Request Forwarding Best Practices?
I'm working with a couple Cisco WLCs and I know that they use information about client signal strength in determining device locations but I was reading up on "probe requests" and found that, by ...
- 27.2k
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What is the 5 level QoS model (through config example)?
I have heard people stating that their network
"operates a 5 level (or layer) QoS model"
Sometimes they also mention a 7 level QoS model. Can anyone provide me with a Cisco IOS config example of ...
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Why does my Cisco 6509 BGP table use two entries in my TCAM?
I have a problem on my Cisco 6509, each entry in my BGP table occupies two entries in the TCAM.
If I show capacity forwarding, I see MPLS entries in L3 forwarding resources.
But, I do not use MPLS on ...
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