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.
3,789
questions
4
votes
1
answer
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How should I diagnose why my Cisco ASA denies traffic?
I have a Cisco ASA, which is denying traffic from 172.16.1.5 to 4.2.2.2 on tcp/9000
How can I diagnose why this is happening from the Cisco ASA CLI?
2
votes
1
answer
558
views
How do I configure an asa 5505 to limit users to only access only company resources and Skype?
I configured an asa 5505 to limit users to only access only company resources and skype.
I got skype working but the company sites in the ACLs aren't accessible.
What am I doing wrong?
ASA Version ...
2
votes
3
answers
3k
views
Firewalls and ACKs
We have a system using Windows 7 that connects to a piece of equipment directly using a crossover cable on NIC1 and it connects to the network on NIC2. It seems to communicate with everything it is ...
4
votes
3
answers
18k
views
Dynamic ARP Inspection ports err-disable with %SW_DAI-4-PACKET_RATE_EXCEEDED
Ports in my network on random switches(connected to Windows 7 workstations) are going into err-disable because of dynamic arp inspection. Ports are going into err-disable because there are too many ...
4
votes
1
answer
1k
views
QoS between two sites
I have a following topology where Internet service providers for both sites provide 10Mbps connection:
There is a GRE tunnel between the sites and I would like to ensure that this tunnel is up even ...
2
votes
1
answer
12k
views
Correct ACL rule to open UDP ports for VoIP
I have the current rules in an attempt to open port 5060 and 10000-20000 for my VoIP provider. We are on a Cisco 1921 router. This ACL is applied to the WAN port on the router facing the ISP. Nmap ...
3
votes
2
answers
2k
views
Large Number of Received Broadcasts on Layer 2 Interfaces
We are running into a situation where we are seeing a large number of broadcasts received on interfaces that are home to servers. I know this is not normal behavior; ARP cache should remember 100 ...
1
vote
2
answers
1k
views
ISP router unreachable by PAT
I just configured PAT in a router but it doesn't work ,,
I write this commands in R1
access-list 4 permit 172.16.0.0 0.0.255.255
ip nat pool AdeNet 80.80.10.20 80.80.10.20 netmask 255.255....
2
votes
2
answers
12k
views
Why does the host in VLAN X flap between ports if LACP is configured?
Aim
The aim is to setup LACP.
/etc/modprobe.d/bonding.conf
alias bond0 bonding
options bond0 miimon=100 mode=4 lacp_rate=1
/etc/sysconfig/network-scripts/ifcfg-bond0
ONBOOT=yes
BOOTPROTO=static
...
0
votes
1
answer
2k
views
Inter vlan can not ping each other
I have this network, but actually pinging between vlans never works. Vlan 10 can ping between its pcs; the same is true for vlan 20, but I can't ping between pcs in different vlans.
I don't know if ...
4
votes
1
answer
584
views
EIGRP to iBGP metric calculation
Consider the following output:
router#show ip bgp vpnv4 rd 300:1 5.5.5.5/26
BGP routing table entry for 300:1:5.5.5.5/26, version 538213
Paths: (2 available, best #2, no table)
Advertised to ...
7
votes
2
answers
5k
views
"transport input" for AUX port in Cisco routers
On physical layer AUX port works on asynchronous serial RS-232 protocol. However, one can specify various application layer protocols like telnet or SSH as allowed input protocols under AUX line ...
3
votes
3
answers
8k
views
MAC Flapping on Cisco 2960G
We've been having an issue for the last few weeks on a relatively small network. The issue started when we swapped a specific Cisco 3750 for a 2960G (there were some other changes), exactly since then ...
2
votes
2
answers
2k
views
OSPF route filtering on Vyatta device
We have a connection between our Vyatta Router to our MPLS VPN Service Provider which is a Cisco device.
We would like to know how to filter the OSPF advertisement routes on Brocade Vrouter 5400 (...
2
votes
2
answers
252
views
List ports which do not have a given property
What would be the easiest was to accomplish this?
Find all ports that do not have 'switchport port-security'
show run | exclude ?
I don't have a swicth with me and packet tracer does not have the ...
5
votes
2
answers
2k
views
Order of entries in "show ip bgp x.x.x.x"
Router# show ip bgp 10.3.3.3 255.255.255.255
BGP routing table entry for 10.3.3.3/32, version 35
Paths: (3 available, best #2, table default)
Multipath: eBGP
Flag: 0x860
Advertised to update-groups:
...
2
votes
1
answer
6k
views
How do testers (i.e. Fluke) get the port they're connected to?
At work I've been tasked to create a program that acts similar to Fluke testing devices (such as LinkRunners) but will be much more extensive and specific to our needs. One of the capabilities that ...
2
votes
2
answers
2k
views
Redirecting remote-access VPN traffic to BlueCoat web proxy
We'd like to get away from split-tunneling on our remote-access VPNs.
The problem I am having is once I turn off split-tunneling, internet bound traffic hairpins on the outside interface without ...
4
votes
2
answers
2k
views
arp inspection with dhcp snooping
My network Figure is :
In this figure switch 3750 is my main switch and all of ACL and vlaning and DHCP server and... comands are in this switch.
I want set ARP inspection configs for security in my ...
3
votes
2
answers
419
views
Cisco BGP Wrong Next Hop
I'm a bit out of my depth with this one & am terrified of making any mistakes.
We have two Cisco routers, R1 & R2, configured with BGP. They both have their own internet connections, however ...
2
votes
2
answers
2k
views
Cisco ASA 5512 internet connection
I'm new into networking and I have a problem setting up ASA 5512 firewall. The problem is that I can't setup internet connection inside my network.
I've created two interfaces WAN with the public IP ...
3
votes
2
answers
12k
views
Cisco router telnet troubleshooting - connection timeout; unresponsive host
I cannot figure out how to establish a telnet connection between two routers in Cisco Packet Tracer. This is a relatively simple process, I know, but I have been back and forth looking for how to fix ...
1
vote
1
answer
383
views
Networking, dedicating bandwidth to specific networks
I need to configure a cisco router where 5mb will be split between 2 separate networks one for voice 1mb and one for data 4mb with voice being the main priority. The only way i can think of doing it ...
4
votes
1
answer
2k
views
Rate limiting specific IP adresses on Cisco 2960S and 2960X series
We are looking into rate limiting some specific IP addresses down to 5mbit for various bandwidth reasons.
Is is possible to rate limit ingress and egress traffic for specific IP addressees on the ...
0
votes
1
answer
120
views
Three Servers on Three IP's
Hello I'm kind of new to networking and I'm having a small problem of.. not knowing where to start.
I have three Windows2012 servers which I would like to assign three IP's from my range given by ...
2
votes
2
answers
803
views
cisco Switch Stack Query
Just a small question can we stack poe and non poe switch (2960x)suppose we have 2 non poe and 2 poe switch , then can we stack this
Can we make stack of 4
7
votes
1
answer
3k
views
BGP authentication-key-chain vs. authentication-key
I found a neat little behavior on a Juniper box I was working with today.
We were migrating from a Cisco ASR to an MX and all of our internet exchange peers that had authentication configured didn't ...
1
vote
1
answer
354
views
ASA 55x - Will management interface shutdown if I remove the IP
I was asked to change the IP address of the management interface on our firewalls but not issue "no ip address" because it will put the interface in shutdown mode which needs to issue no shut again ...
4
votes
1
answer
3k
views
Replacing Line-Card - Catalyst 6509-E - Questions
I have been handed a ticket to work an RMA for a failed line card in a Cat6509-E. Not ever having worked with these devices before I had a few questions:
The config that applies to the ports on the ...
8
votes
5
answers
8k
views
Cisco Static NAT with route-maps
Update:
Seems that route maps only match on IP addresses, not on the ports. Had another situation this week on a different device, model and software version. Ended up changing the NAT statements to:
...
3
votes
1
answer
9k
views
Cisco router + cable modem - How to configure routing?
I am starting up a small business network. The ISP has provided us two distinct static IP ranges; understand that the actual IP addresses provided by the ISP are in routable Internet space.
Network ...
5
votes
1
answer
1k
views
What is the technical reason for PaGP Silent mode and why is it a default?
So I have done a little reading around PaGP silent mode, and I don't understand why it exists. My understanding is from:
The silent mode is used when the switch is connected to a device that
is ...
7
votes
3
answers
25k
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Difference between trunk and access/voice port [duplicate]
Is there a difference between the following two configurations on a cisco device?
int g0/1
switchport mode access
switchport access vlan 10
switchport voice vlan 20
and
int g0/1
switchport trunk ...
10
votes
4
answers
191k
views
What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch?
I wonder what can cause the first line output of the command show interfaces to be: FastEthernet is up, line protocol is down.
In other words,
Is the cable that is connected to the local interface, ...
1
vote
0
answers
6k
views
VPN tunnel connection issue
My company has 2 ASA firewall with model 5510 & 5512 in difference country, I was connected it via IPSEC VPN. It can work in normal until 2 weeks ago.
I checked from log in ASA5512 firewall, it ...
6
votes
3
answers
24k
views
Can Cisco Catalyst switch get IP from DHCP server?
This may be stupid question as I don't have much knowledge in networking.
Anyways, I have Cisco Catalyst 2960 switch and I'm curios if I can configure it to get IP configuration from DHCP server, ...
1
vote
3
answers
1k
views
Howto configure router to add to private network LAN? [closed]
first I'm gonna warn that I'm fairly bad at understanding networking so kinda nervous about posting this.... I'm using NetsimK to study setting up a network for a college assignment, I'm finding it ...
4
votes
1
answer
1k
views
In a multi-homed BGP network I am looking to create a default route to ISP 1 with ISP2 as backup
I do however, need ISP1 to automatically become the primary route once the route is back up. There are only 3 routers in this topology, router 1 and router 3 are connected with ISP1 and ISP2 ...
1
vote
1
answer
2k
views
Cant access remote management interface
The data link is completely okay. I can access MGMT IPs of routers (10.0.0.2 |10.0.0.4) from 3750 but not from PC. I can access 3750 MGMT IP (10.0.0.1) from PC . Any idea why ?
Note : All management ...
2
votes
1
answer
570
views
HW State: DEAD - Cisco 3925
I received an alert stating that a crypto engine was 'dead'. I did a bit of digging and was able to find some output to validate this:
#sh crypto eng config
crypto engine name: Virtual Private ...
3
votes
1
answer
1k
views
CME and 2951 embedded service engine issue
I have a client with CME on a 2951 router. They lost the login creds for CME and I attempted to reset the login via creating a session to the embedded service engine. When I tried to do this I ...
5
votes
2
answers
1k
views
Enable SNMP traps for ACLs using Cisco IOS?
Does anyone know if it's possible to enable SNMP traps to be sent from a Cisco IOS device when an ACL blocks traffic? I'd like to send a trap whenever a deny statement gets a hit.
I've only been ...
3
votes
1
answer
448
views
Securing Console Serial Ports
I am looking to secure our console ports in our remote console router equipped with HWIC-16A cards and RS232 cables.
As the network admins, we usually login to these routers first (using privilege 15 ...
3
votes
1
answer
13k
views
What does 'clear int giX/X/X' do? Cisco
Simple question
What functionally happens when executing 'clear int giX/X/X' on a switch? The port config looks the same afterwards, I see no difference.
1
vote
0
answers
88
views
Cisco ASA Hung - Error: "i82546GB/enadap_get: 2 not null"
We configured our new cisco ASA 5520 firewall device to act as RAVPN peer device. AAA is configured in such a way that user will get authenticate at our ACS 5.4 server. After completion of all other ...
6
votes
1
answer
5k
views
Cisco OSPF type 5 /32 routes in database, but not in routing table
Our network runs OSPF for IPv4 on Cisco hardware. The following image shows the relevant topology:
Topology
Problem Statement
We have a Cisco ASA firewall, which also is the VPN gateway for ...
5
votes
1
answer
9k
views
UDLD state: tx/rx loop detected
Relevant Log messages
Feb 1 03:39:08.338 EST: %IPV6-4-DUPLICATE: Duplicate address FE80::212:44FF:FE4D:4400 on GigabitEthernet8/20
Feb 1 03:39:08.904 EST: %UDLD-SP-4-UDLD_PORT_DISABLED: UDLD ...
4
votes
1
answer
2k
views
Cisco ACL to block connections with ICMP or RST
The Cisco "deny" ACL seems to quietly drop TCP/IP packets. Is it possible for it to send either ICMP responses or TCP RST's in response to a denied request?
3
votes
1
answer
661
views
Simple egress block ACL on Cisco IOS
I have a Cisco 890 with IOS 15.4.
As brief summary of my configuration, FastEthernet 8 is the uplink and NATs the other interfaces (which are grouped into vlan 1).
I'm trying to block access to a ...
3
votes
1
answer
1k
views
ASA 5525-X PAT only for one IP subnet
Can an ASA 5525-X dynamically PAT one IP subnet of private addresses (from inside port to outside port) and simultaneously pass another subnet through without PAT?
I have a public IP address on the ...