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.

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19
votes
4answers
24k views

Cisco APs ignore DHCP Option 43 and use CAPWAP UDP broadcasts

Background I am trying to redeploy Cisco 1242 LWAPs on new Cat4507R+E switches, which means the IP address of the WLC is changing for that LWAP. For some reason, I have to configure ip helper-...
8
votes
1answer
601 views

packet capturing

I am having a hard time understanding certain terminology and setup when it comes to packet capturing. Example. At my company we use NetScout and the various services such as PFS(Packet forwading ...
10
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2answers
12k views

How do you throttle Dropbox Traffic?

It appears that Dropbox uses Amazon AWS for it's storage, so I am not able to just block or trottle traffic to dropbox.com Since there are a lot of web services that rely on AmazonAWS, I cannot just ...
14
votes
4answers
12k views

How do you block bit torrent traffic with a Cisco ASA?

I have referenced an old external Cisco article on how to block Bit torrent traffic referenced on-line Here This procedure I have found only works 50% of the time. I find blocking bit torrent ...
7
votes
1answer
539 views

Can I use a reflexive ACL in place of a Firewall?

I'm studying CCNA and i've just learnt about Reflexive ACL's. Just wondering how secure or insecure it would be to use an ACL in place of a firewall. This was a LAB router that I would like to set ...
8
votes
1answer
2k views

Switch replacement procedure 3560G to 3750X

My company will upgrade two Cisco 3560G switches (an HSRP Active & Standby pair) to two Cisco 3750X switches in a stack. I need to make a switch replacement procedure starting from removal of the ...
9
votes
3answers
10k views

Two SSID's for same VLAN - problems?

I want to test 802.1x on a test SSID. Wasn't sure if making a test SSID associated to a VLAN that already has another SSID associated with it would cause a problem with the customer facing SSID. Ex. ...
7
votes
3answers
802 views

Cisco 1800 drops link to ADVA

I'm having a problem getting a Cisco 1841 connected to an ADVA WAN box provided by TWTelecom. They've given me instructions to force the fasteternet0/0 100 full duplex on interface 0/0, which I have ...
12
votes
2answers
321 views

Do unused Cisco IOS features take up RAM/CPU resources?

For example, let's compare IP Base vs. Advanced Enterprise Services. Let's say you have advent installed, but you're only actually using the features relevant to ipbase. Other than flash memory space, ...
9
votes
4answers
53k views

How to find a list of devices connected to my network (IP's and MACs)

I am trying to get a list of the devices that are connected to my Cisco (Catalyst 2960) switch. Preferably through SNMP. Here is what I've already done: I was able to retrieve the ARP table from the ...
18
votes
5answers
89k views

About the switchport mode

I am new to network Engineering. I find it is hard to distinguish and understand different switchport settings. Why can I have a switchport set to access, auto, or dynamic? What are they used for? ...
5
votes
2answers
2k views

HSRP + OSPF over tunnel interface

We have 3 sites over an MPLS. Each site has 2 x Cisco 2911's running HSRP. Each site has a tunnel interface from it's local site to the remote site over the MPLS. The tunnel interfaces are mirrored on ...
9
votes
1answer
2k views

Globally disable QoS on Cisco 3750 in production

I suspect some issues with faulty QoS settings on a 3750 stack running in a 24x7 environment. The 3750 mainly routes between vlans on a lan segment. Since it is a lan device (not terminating any wan ...
4
votes
1answer
535 views

Allow Network to Network traffic for specific port, Cisco PIX v6.2

simple question. I am trying to allow traffic from NetworkA to NetworkB through and old PIX firewall. The firewall has a leg into each NetworkA+B. nameif ethernet1 inside security 100 nameif ...
6
votes
1answer
4k views

DNS options Ironport Web security appliance

I'm running a Ironport WSA in transparent mode. In advanced proxy config - DNS Options I find the following: Find web server by: Specify how the appliance should find the location of the requested ...
16
votes
4answers
52k views

Bad Mask for IP Address Error

I'm not too clear on subnetting rules and experienced an error when I tried to assign 148.26.1.176/28 to an interface on my Cisco router. Can someone please explain why it was not allowing me to ...
9
votes
4answers
5k views

Delay or Offset-List for EIGRP tuning?

Studying for CCNP-ROUTE - everything I read says it's preferable to use delay and offset-lists for metric tuning vs. say bandwidth in EIGRP. In practice what is more commonly used out of those two ...
11
votes
1answer
12k views

Can adding VLANs to a VPC be done hot?

In this scenario, we have a VPC '17', consisting of two single port port-channels 'po17'. There are 2 x N5K's (5548s) - so po17 from both sides combine to create the VPC. The downstream devices are ...
5
votes
2answers
5k views

How do I tag traffic with a DSCP value on an ASA?

I have a SIP Server that does not put a DSCP code on it's traffic. This server is behind an ASA, and I want to prioritize its traffic passing through an ASA from the private to public network. I am ...
9
votes
4answers
2k views

ASA FTP Special Character in password issue

I am trying to copy a show tech from an ASA to a remote server via FTP. My issue is that the password I am providing has a '@' and it is being interpreted incorrectly by the CLI. I have tried putting ...
6
votes
2answers
2k views

Cisco 7609-S Line card error counter is regularly exceeding threshold

I am receiving the following syslog messages on a 7609-S. Jun 17 11:52:27.560 BST: %CONST_DIAG-SP-4-ERROR_COUNTER_DATA: ID:47 IN:4 PO:255 RE:169 RM:255 DV:5 EG:2 CF:10 TF:472 Jun 17 11:52:27.560 BST: ...
9
votes
3answers
17k views

ASR1K feature licensing navigation

I'm looking at deploying a pair of ASR1001 units at the WAN edge to support 2x IP Transit and 1x Peering services. I need to do IPV4 and IPV6 eBGP and iBGP to advertise the peering routes into the ...
8
votes
2answers
6k views

How to host server in DMZ zone of an ASA

I have an ASA5525-X with 9.1.2. On it are several interfaces, but primarily I'm looking at: (fake subnets) inside 10.0.0.0/24, security level 100 outside 10.0.200.0/24, security level 0 DMZ 10.0.100....
6
votes
1answer
2k views

WS-X45-SUP6-E / WS-X45-SUP7-E compatibility w/4510R (non-E)

The EOL announcement for the Cisco WS-X4516 on a 4510R (non-E series chassis) states that the WS-X45-SUP6-E is a replacement though this SUP is for the E-series chassis. Incidentially, the SUP6 is ...
8
votes
2answers
680 views

Is 802.11k a security risk?

I'm looking at enabling 802.11k on my Cisco WLC. I see that it is a per-WLAN feature and that leads me to wonder if there might be any reason to not enable it? Specifically, does anyone know if there ...
16
votes
3answers
10k views

Backing up Cisco router configuration - including ssh keys

We have some Cisco 2821, 2921 and 1921 routers in our shop. I can back up and restore the configurations by copying out or in the startup-config file, but what about the keys for ssh? I don't want ...
6
votes
3answers
14k views

Cisco IP Phone 7900 Series - Auth Fail on boot

I have several hundred Cisco 7900 series IP phones, (7911, 7942, and 7962 models) that have been sitting on the shelf as replacement stock for several years. Now as we deploy them, we are ...
6
votes
1answer
2k views

How do I create an SSL CSR via CLI for Cisco Prime?

I'm trying to create a csr for a cisco prime server. I managed to create a csr and put it in the "defaultRepo", which is local on the disk. After what I've read I need to create a certificate repo ...
6
votes
1answer
253 views

Why there is a maximum of 4096 queues in WFQ?

In QoS there is a variety of Queuing methods and one of them is WFQ, which organizes the flows in different queues where each queue has a weight that determines which flow will go first. Now for ...
10
votes
1answer
2k views

Using RADIUS to restrict SSID on Cisco Aironet

I would like to use my RADIUS server to restrict access to configured SSID on a per user basis. According to the documentation linked above i add the following attribute to a test user: ospite-5vh ...
5
votes
2answers
1k views

How do you configure a Lan to Lan VPN without using your outside interface IP address?

I have two /28 subnets A & B. My main vpn peer ip is in subnet A, it is also my outside interface address. I have free IP's in subnets A and B and id like to use one of them to host lan to lan ...
0
votes
1answer
520 views

How to select an IOS update (cisco)? [duplicate]

2) How do you go about selecting the best IOS version to be on after you determine you need to update? 3) If you want to upgrade to a particular version, how do you check whether it's OK to move up ...
10
votes
1answer
4k views

Is ATM still used as a transport protocol?

In addition to reading new material, I enjoy reading older networking books in attempt to see where we've come from and possibly where we're going. Currently, I'm reading a book called Cisco LAN ...
10
votes
4answers
4k views

how to get scp via snmp to work with cisco routers?

I have a lab setup where I'm trying to use SCP via SNMP to a cisco router.I found some online documentation such as: http://ccie20728.wordpress.com/2008/05/20/get-the-cisco-configuration-over-snmp/ ...
10
votes
1answer
4k views

How can I make a PVST+ switch root towards MST network?

In a network where the majority of the switches are running MST but a select few are still running PVST+, how can the PVST+ switch be configured to be the root of the spanning tree? Topology below: +-...
3
votes
2answers
3k views

How do I set up secure remote access to my home lab network?

My current setup is the following: ATT ISP ---- ATT wireless router ---- cisco 890 wireless router My cisco 890 is for internet and remote VPN access from home to my company, however, I don't have ...
9
votes
2answers
491 views

How to handle performance degradation deep in your provider's network?

What are some possible ways to detect packet loss deep in a provider's network that is several hops away? With multiple providers peered over BGP on our Internet edge routers, I need to be able to ...
8
votes
2answers
507 views

Determining optimal bandwidth needs for the office

We're currently using the Cisco 1921/K9 router along with SG300 L3 switch and other L2 switches in the office environment. We're hooked up to a 10M fiber line for internet but not sure if we need that ...
10
votes
3answers
4k views

Inbound BGP load-balancing from same ISP router

I have two BGP routers for DIA with an issue with one provider in that the two links to this provider land on the same SP router. My ethernet handoffs via two separate MetroE links from another ...
9
votes
1answer
160 views

EIGRP FD not the same in topology table

In EIGRP when showing topology table, i notice in some entries are like below: P 10.1.6.0/24, 1 successors, FD is 793600 via 10.1.2.2 (2195456/281600), Serial0/0/0 via 10.1.3.2 ...
9
votes
3answers
446 views

Cisco 2901 - Determine if bundled T1s are up based on bandwidth?

I have a Cisco 2901 at a remote branch office connected via ge0/1 to an Adtran that is managed by TW Telecom with 8 T1s bundled together for an MPLS circuit. I don't have access to the Adtran gear, ...
9
votes
3answers
1k views

VM on a client connected to a Cisco 1262 unable to DHCP (but IPv6 works fine)

I recently replaced wireless at a site from the internal AP on an 877-WM with a (standalone) 1262 running 15.2(2)JB. I've configured the AP pretty much the same as I always do for Cisco AP's for ...
8
votes
3answers
4k views

Traffic Policing

I know traffic policing isn't something that you normally find in a LAN environment, and I wish I wouldn't be finding it in mine. That being said... I have no choice. The device is a 3750X. The ...
9
votes
4answers
794 views

How does one specify certain IPs or MAC addresses for NBAR policy enforcement?

In an office environment, if I wanted to block youtube using a Cisco ISR router, I would set up the following with NBAR: class-map match-all YOUTUBE match protocol http host "*youtube.com*" ! policy-...
3
votes
2answers
781 views

Difference between MSC-A, MSC-B and FP-40

What's the difference between MSC-A MSC-B FP-40 on a CRS-1 8-S?
4
votes
2answers
868 views

Setting the same gateway address at a DR site as our main site

I have a question about routed traffic across a site to site VPN between 2 Cisco ASA 5510's. We have our office side and our DR side and the question is could I have an IP conflict of gateway IP ...
6
votes
1answer
629 views

Migrating from PIX/VPN 3000 to ASA

In a project to replace the last Cisco PIXes and VPN 3000 Concentrators we have [finally], I've already spec'd out the new ASA 5515-X and 5545-X's. I have no experience with the X models; only exp ...
13
votes
3answers
65k views

What is the meaning of RSSI?

When using mobile 3G routers, you see in the output of the "show cellullar 0 all" command. What is the significance of this value? Is this interpretation the same when talking about 2G or 3G? Ex: ...
9
votes
2answers
5k views

Configure External Interface for DHCPv6 client on Cisco IOS

What are the necessary steps to configure IOS 12.4(25f) to support IPv6? Comcast is the ISP, and I'll be using a Server 2012 box for internal DHCPv6. I'll need to grab a DHCPv6 address from Comcast ...
10
votes
4answers
18k views

Setting up DHCP server on the router or on the switch?

We're using the Cisco 1921/K9 with a SG300 L3 switch. Does one set up DHCP server on the router or on the SG300? If both is capable, what is the reason to choose one over the other? Note: I have 4 ...