Network Engineering Stack Exchange
Network Engineering Stack Exchange

Most Popular

more tags
1500 questions
8
votes
2 answers

NAT with VPN Site to Site and Remote LANs with same IP address

I have a ASA5510 to connect clients to my company. I use a site-to-site IPSec VPN with a variety of vendors on the other side (Cisco, Sonicwall, Zyxel, Checkpoint, etc...). For every remote LAN, I translate the network client in a single IP address;…
lmperso
  • 81
  • 1
  • 2
8
votes
2 answers

What's the difference between Ethernet link and Serial link?

Sometimes we see router connected use Ethernet link, sometimes use Serial link, what's the difference between them? and in what scenario we use them?
26334_zeal
  • 339
  • 2
  • 5
  • 12
8
votes
4 answers

QoS on a dedicated VOIP network

Is there any point in enabling QoS on a dedicated VOIP network that only has VOIP traffic?
Brian Parker
  • 83
  • 5
8
votes
1 answer

Run MACsec and VLAN in parallel?

MACsec (IEEE 802.1ae) adds a security tag to an Ethernet frame and encrypts the IEEE 802.1Q field, the EtherType and the payload field. If you want to use VLAN, you need the 802.1Q field to announce the VLAN ID. The EtherType is usually set to…
null
  • 215
  • 2
  • 6
8
votes
3 answers

Using Fabric on a Cisco device : "Line has invalid autocommand"

I wasn't sure where to ask this but it seems to be something on the switch side so I thought I would start here first. I am working on a little project to automate updates to config files in bulk using Fabric. I have everything installed and…
jmreicha
  • 272
  • 3
  • 10
8
votes
4 answers

Why is a TCP Socket identified by a 4 tuple?

Newbie to networking here. I'm reading the Computer Networking (3rd edition) book, and in section 3.2 they are discussing multiplexing / demultiplexing for both UDP and TCP. In the UDP protocol, a socket is uniquely identified by the source IP and…
Steven L.
  • 183
  • 1
  • 1
  • 4
8
votes
3 answers

Need help understanding how packets travel across the internet

I've been learning about networks recently at a new job, and I did a presentation on what I've learnt so far. When I was describing the relationship between the datalink and network layer, I mentioned that datalink handles the hops while network is…
jwoff
  • 83
  • 1
  • 5
8
votes
7 answers

Juniper EX-series: How can I transfer a config from one switch to another?

I have a lab EX-2200 that has a config on it that I now want to replicate onto four more EX-2200's... I'm sure there's probably an easy way to do this, but couldn't find it on the Juniper KB or by (a minimum amount of) Googling. Anyone here know?
Will Dennis
  • 461
  • 1
  • 5
  • 16
8
votes
2 answers

What does the output of this tcpdump mean?

Bellow I show the output of my tcpdump What does the first two mean lines means(what are all the question-marks meaning is this a sign of a intruder)? I am especially interested in the meaning of what this mean: PTR (QM)? _airplay._tcp.local. PTR…
jennifer ruurs
  • 183
  • 1
  • 1
  • 4
8
votes
2 answers

Cisco Nexus Fabric Extenders with 10G-SFP in path?

We are looking to deploy a new data center build-out with Nexus 7ks and Nexus 2ks(FEX). I know the Nexus 2ks come bundled with the Fabric Extenders to be used to uplink to the Nexus 7ks. Our plan however is to put Gigamon fiber taps in-line of all…
ge0ff73
  • 271
  • 1
  • 8
8
votes
3 answers

whois 243.25.203.20

I see this ip address actively accessing gmail account in spite of 2-Step Verification. whois 243.25.203.20 produces following message: No whois server is known for this kind of object. How can I find out what functionality uses this ip?
Peter J
  • 83
  • 1
  • 5
8
votes
1 answer

Why is the ethernet payload fixed between 46 and 1500 bytes?

Can anyone explain why the ethernet payload size is fixed between 46 and 1500 bytes ? I read so many articles never get the clarification?
user2720323
  • 1,611
  • 9
  • 20
  • 26
8
votes
3 answers

How to connect 3rd party SFP to the cisco switch?

I am trying to connect "sfp-1ge-fe-e-t" sfp module to CISCO Catalyst C3560G-48TS switch. When i pluged module to the port and following error was shown: %GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port Gi0/49 has bad crc Then I searched…
Simral Abdurahim
  • 145
  • 1
  • 1
  • 7
8
votes
3 answers

routing between vlans not working

I need to put a Cisco router behind an ISP router. (The ISP doesn't allow us to use their modem only.) I've called the ISP technical service and they've set up the connection with me. Their router will be used as a gateway for the Cisco router. I…
RobbeM
  • 213
  • 1
  • 6
8
votes
2 answers

VLAN load sharing on Metro-E links between two Juniper EX 4200

We have Juniper EX 4200 as core switch at two sites connected Cisco 2960s and Cisco 3560s (access layer switches). For even-numbered VLANs, one Juniper switch is root bridge and for odd-numbered VLANs, other Juniper switch is the root bridge. We…
starcity
  • 81
  • 3
1 2 3
…
99 100