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1500 questions
6
votes
2 answers
Issues with Juniper MX-series iBGP routes
I have a simple setup:
2x Juniper MX-Series routers each having one uplink to a transit provider
iBGP session between both routers (point-to-point)
For testing purposes I've disabled the uplink from R2 to the transit provider. All routes are…
WinkyWolly
- 257
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6
votes
1 answer
Why is there a separate set of 10 Gigabit fiber-optic transmission standards for WANs/SONET?
So, I'm reviewing the different IEEE transmission standards for an exam, and I've noticed that for the 10GBASE-X standards, there's two different sets of fiber-optic standards, 10GBASE-xW and 10GBASE-xR. It's noted that the W standards are for WANs…
Xovvo
- 95
- 5
6
votes
3 answers
Understanding ARP and Routers
Let's say there are two PCs, PC A and PC B.
PC A wants to communicate with PC B, such as sending a message.
I need to describe the arp packets for this task.
Known details:
PC A -> SW 1 -> Router -> SW 2 -> PC B
Host A and host B are in a different…
NetworkNewbie
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6
votes
1 answer
How does router advertisement in IPv6 avoid IP conflict?
If a router advertisement sends the range of subnet, and the client can choose an IP from it, how is there no conflict with another client that has chosen the same address?
Omer Anisfeld
- 163
- 6
6
votes
4 answers
How can I view bandwidth use by ip/host on a Cisco router?
My company has a 100mbps Internet connection and we have recently experienced extreme slowness when using the Internet (our provider's speedtest page indicated .25 Mbps download speed). When we contacted them about it, they said it's because our…
vrtigo1
- 161
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6
votes
3 answers
What is the characteristic of spoofed ARP packets?
Hi what is the characteristic of spoofed ARP packets? I want to know how to detect it but before that I have to know how can I call a packet a spoofed packet. I hope you can help me thank you.
Tiffany
- 85
- 7
6
votes
1 answer
Cisco: storm-control unicast
Within a typical service provider environment I can see how broadcast and multicast storm control can be useful. I am confused regarding unicast storm control though.
Reading the Cisco docs online they give examples such as protecting against port…
Baldrick
- 5,310
- 8
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- 79
6
votes
4 answers
Why does it say, that a Switch can segregate the collision domain?
In general, the Ethernet Switch use RJ-45 link to connect the Hosts and the Switch uses Store and Forward mode.
So, why is there a saying:
Switch can segregate the collision domain
I thought the Switch Store and Forward mode and RF-45's full…
qg_java_17137
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- 13
6
votes
3 answers
OSPF Area Backbone(0) is Inactive
I am having a puzzling issue with OSPF connectivity on one of my routers. The other routers in my network have formed an adjacency and are working correctly, but this last one is a case I've never seen before. All of the interfaces on the remaining…
THE DOCTOR
- 963
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6
votes
3 answers
How not to route on a Cisco router
So we have a router, with a switch card interface, 8 ports
Say I have 4 VLANs (A,B,C,D) on it, with 2 switch ports in each.
Each VLAN (i.e. all ports) can communicate with each other, because naturally they are all connected to the one router...…
user10021657
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6
votes
2 answers
What do exclamation '!' and period '.' mean in a switch config file
what do the ! and . mean in switch config files?
Current configuration: 1363 bytes
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Switch A
!
Command Purpose
Step…
robinhoodjr
- 209
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- 4
6
votes
1 answer
Why do DHCP servers lease IP address based on Option-61 (Client-ID)?
Why do DHCP servers (specifically Cisco) use "Client-ID Options", not the CHADDR (client MAC) in the DHCP request, for static binding?
From: Configuring DHCP
All DHCP clients send a client identifier (DHCP option 61) in the DHCP packet. To…
t3mp
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6
votes
1 answer
What is "interarrival jitter" in mtr?
What is "interarrival jitter"?
I've noticed it's available in mtr, but the calculated values don't make that much sense — they seem to be much larger than even the max jitter value. What would they be of use for?
Cns# mtr --report{,-cycles=100}…
cnst
- 417
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- 12
6
votes
2 answers
Help with basic network security issue
I recently took over managing my church's IT resources. Previously it was managed by nobody and so was subject to any random person or vendor's half-baked idea for building out the network. Right now we have a wired network and a wireless network on…
Ant
- 163
- 3
6
votes
1 answer
Junos: Policy-Statment and AS-Prepends
I am trying to create a policy-statement to prepend the local AS number 5 times (assuming it is AS1234) before advertising local routes up to a new upstream transit provider (no inbound traffic is desired via this upstream). MED and communities are…
Baldrick
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