Network Engineering Stack Exchange
Network Engineering Stack Exchange

Most Popular

more tags
1500 questions
7
votes
1 answer

Cisco ISE backup shows as success but no data was written to backup server

I'm trying to back up a Cisco ISE server (version 1.2.0.899 patch 4) via sftp. I configuered a repo via the web gui. I added the hostkey (for the backup server) via the command line. I make sure the path exsites on the backup server. I then start a…
evolvd
  • 754
  • 1
  • 11
  • 19
7
votes
1 answer

Will a 3rd party SFP module void Cisco warranty?

Will using a non-Cisco branded SFP module void any warranty with Cisco (either with the switch or network module)? The SFP we are looking for more cost effective alternatives is SFP-10G-SR-S in a C9300-NM-8X.
Ryan F
  • 93
  • 3
7
votes
2 answers

What do input discards on switch ports indicate and how can one track down their cause?

The conditions under which a switch will discard outbound packets on particular ports are fairly well established in many basic training materials, including those for CCNA. However, input discards are typically less well-documented. Some reasons…
Paul Gear
  • 438
  • 1
  • 5
  • 14
7
votes
1 answer

AAA Authorization Timeout

Log into a Cisco IOS device with TACACS Authorization enabled Do a command that causes the device to lose access to the TACACS server Enter a command that requires TACACS Authorization By default, the timeout appears to be about 30 seconds before…
Keller G
  • 1,589
  • 10
  • 18
7
votes
3 answers

Creating a JunOS firewall filter based on dynamic routing properties

One of my BGP transit customers has asked me for a solution to make it easier for him to blackhole traffic within our network when he's suffering from DDoS attacks. Usually, BGP blackholing is done by blackholing the target, however, my customer is…
Teun Vink
  • 16,953
  • 6
  • 44
  • 70
7
votes
1 answer

tcp.length and tcp.data wireshark filters

I was playing with Wireshark and noticed two filters: tcp.len and tcp.data. What is the difference between the two? As far as I know, the tcp.len (length) field tells how many bytes of data travel within a segment, correct? thanks in advance :)
Matjaž
  • 205
  • 2
  • 3
  • 7
7
votes
4 answers

How OSPF decides a network to be a stub network?

In RFC 2328 it mentions that link-state information of all Loopback interfaces and all interfaces with network mask as /32 (host ip addresses) are advertised as stub network type. Now what about the cases where a interface with /24 mask is connected…
Hemanth
  • 1,114
  • 11
  • 22
7
votes
4 answers

What is Null 0 interface?

In which case is ip route 10.1.0.0 255.255.255.0 null0 used? Thanks in advance. This question is a repost of the same question in The Cisco Learning Network; however, the answers are unique to Stack Exchange.
Trojan
  • 1,398
  • 5
  • 17
  • 29
7
votes
1 answer

Will hosts do IP Fragmentation?

I heard routers alone do fragmentation. When a host is connected to the network with ethernet cable, how does it keep the MTU size as 1500? Will the host itself fragment and send only 1500 byte payloads in the ethernet cable?
Jinga
  • 71
  • 2
7
votes
3 answers

Multi-tenancy TACACS server

Is it possible for Cisco ACS 5.4 (or any other version) to work in a multi-tenancy environment? I would like to have two ACS servers, one primary, one secondary, with completely different routing (but obviously keep access to each other for…
Steve Wright
  • 91
  • 3
7
votes
2 answers

Why BGP max message size is choosen as 4096 ? why not 2^16?

BGP message length in of 2 bytes. So why can't the max bgp message size be 65535 ? why is it 4096 ?
Hemanth
  • 1,114
  • 11
  • 22
7
votes
1 answer

Cisco: Reliable fast BGP failover when mixing BGP NHT and BFD

When running BFD on interfaces between two directly connected iBGP and IGP neighbours, is it more stable/reliable to use BFD for fast IGP reaction times and BGP Next Hop Tracking for faster BGP reaction times (rather than BFD for both)? The reason I…
jwbensley
  • 5,290
  • 7
  • 37
  • 79
7
votes
2 answers

Why does 1000BASE-T need Auto-MDIX?

A 100BASE-TX PC interface sends out its frames on pins 1,2 and receives frames on pins 3,6. If we connect this PC's NIC with that of another PC we cannot use a straightout cable, because the frames sent by the first PC would arrive on pins 1,2 of…
Marcos Gonzalez
  • 1,041
  • 1
  • 12
  • 13
7
votes
1 answer

Upgrading ASA and ASDM on a ASA5510

I have a single Cisco ASA 5510 in production. It has: ASA version 8.0(2) ASDM version 6.0(2) 1GB RAM (upgraded recently from 256MB) 64MB Flash I have backed up the flash and the configuration. We need to upgrade the ASA version to 9.1(4) and ASDM…
thilina R
  • 611
  • 2
  • 11
  • 23
7
votes
3 answers

Edit Cisco IOS ACL without hanging the router

I have a Cisco Router 1941 Series and I want to make some changes to the access-list on the router. I got to know I will have to delete one of the list and then re-add everything again with my additional ones included while stating the deny ones at…
Laredo
  • 569
  • 2
  • 7
  • 15
1 2 3
…
99 100