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1500 questions
18
votes
1 answer
MPLS auto-bandwidth balancing
I operate an MPLS/IP network that utilizes auto-bandwidth to measure bandwidth utilization and signal RSVP accordingly.
How can I maintain balance across my LSP paths such that one large [P router]-to-[P router] path/flow doesn't saturate any one…
jof
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18
votes
3 answers
Adding a simple VLAN on a Juniper MX
after years away from JunOS, working with Foundry (now Brocade) routers, I find myself with a new Juniper MX10. All I want to do is create a simple VLAN such that two ports share one routing interface, which has one IP address. On a Brocade, this…
Matt
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18
votes
5 answers
Why use PPPoE and not use IP directly?
As far as I understand, PPPoE operates over ethernet, so for PPPoE to be usable you should already be able to send Ethernet frames to your ISP.
At that point, why use PPPoE at all? Why not just run IP directly over that Ethernet-like link, assign an…
André Borie
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18
votes
3 answers
How does multihoming work with ipv6?
What are the differences between multihoming in IPv4 versus IPv6?
Can an enterprise request a provider-independent IPv6 address space from its RIR/LIR which can be advertised to multiple upstream providers via BGP just as in IPv4?
Are the rules…
User123456
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18
votes
3 answers
Can my MAC address be identified by a web site?
Can my MAC address be identified by a web site when I access the site?
Does it make a difference if the site requires me to upload files?
MRTgang
- 283
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18
votes
4 answers
Is GRE necessary for an IP-only tunnel?
I need to build a simple point-to-point tunnel to connect an office through an area of the network we trust but directly don't control. Does the tunnel need to be GRE-encapsulated or can I use direct IP-in-IP? (We won't be using IPsec for this…
Jeremy Stretch
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18
votes
7 answers
Cisco command to show which interfaces an ACL is applied to
For Cisco routers and switches, is there a show command, or something similar, that will display what physical and logical interfaces an ACL is implemented on and what direction it is applied in?
I am looking for something simpler than a show run |…
Adam Loveless
- 3,129
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18
votes
2 answers
In which OSI/TCP-IP model layers do BGP, RIP protocols belong?
We know that in the OSI or TCP-IP model, the higher layer utilizes the services offered by the lower layer. For example, the data link layer uses services offered by the physical layer, network layer uses services offered by the data link layer and…
Mahesha999
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18
votes
2 answers
Cisco - display ALL routes using a single command
In Junos when you use a show route it displays the routing tables , starting with inet.0 ( global routing table) and then listing each VRF in alphabetic order.
I am after a similar command , for the following reason , new WAN deployment: remote…
DrBru
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18
votes
7 answers
Best practice for the combination of HSRP and ECMP
The combination of ECMP (or other causes of asymmetric paths) and HSRP is broken by default in Cisco IOS; the default behaviour with this design floods unicast traffic excessively.
What is the best-practice for using HSRP with ECMP to prevent…
Mike Pennington
- 29,989
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18
votes
4 answers
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-addresses on my AP vlan to jumpstart communication…
Mike Pennington
- 29,989
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- 152
18
votes
6 answers
Reason for half-duplex mode in Ethernet?
Half-duplex connections were popular at the time of 10Mbps and 100Mbps Ethernet, and, according to standards, it is allowed also in case of 1Gbps Ethernet.
Am I correct that half-duplex mode support in Ethernet chipsets was crucial in case either a…
Martin
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18
votes
5 answers
Why is the U/L bit inversed in EUI64?
This inversion is bijective, so I can't figure out what is it's use.
Silviu
- 413
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18
votes
3 answers
Writing text to the log
Is it possible to write an arbitrary line of text to the log of a Cisco IOS 12.x device?
I should like to be able to put in markers when fetching configs via TFTP and I would like to be able to have log lines á la
May 30 14:14:00.000:…
Jan
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18
votes
4 answers
Why does WLAN use Collision Avoidance and not Collison detection?
I am searching for this answer for quite some time now. Why there is CSMA/CD in LAN but CSMA/CA in WLAN?
The best explanation I could find is "due to extreme ratio in transmitting and receiving power, it is very impractical to transmit data on the…
vish213
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