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1500 questions
10
votes
4 answers
Strange 2960 behavior on my network
I have a bunch of Cisco routers and switches in our buildings. Basically, every building has one router and one or more switches. I use just two VLANs for each building: VLAN1 is the data VLAN (native as well) and VLAN200 is the voice VLAN. Each…
Abdel
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10
votes
5 answers
What Exactly is SDN?
Is SDN a buzzword or is it a protocol, standard, or recommendation?
What differentiates SDN from VMware NSX, for example?
Ronnie Royston
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10
votes
3 answers
Is Ethernet a protocol?
When I googled I found a lot statements about this. Like..
Ethernet is not an application protocol. But I'd still give it the description "protocol".
A network protocol defines rules and conventions for communication between network…
apm
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10
votes
1 answer
Can I poll firewall counters on Juniper routers via SNMP
I have a firewall counter on a Juniper MX router (set firewall filter myfilter term myterm then count mycounter) and want to poll its packet/byte count via SNMP. I searched for an OID but I'm unable to find one. Is it possible at all to poll…
Sebastian Wiesinger
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10
votes
3 answers
What is the minimum MTU size?
The maximum size is 1500 Bytes. Is there a lower limit? 1? 64? Must it be a multiple of two? Is there somewhere I can look to learn more?
tarabyte
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10
votes
2 answers
Does port mirroring cause additional latency?
If I'm sending traffic from host A to B by a switch, will enabling a mirror/SPAN port increase the time it takes for my frames to get from A to B?
Nb: I'm not worried about the time it takes for the mirrored frame to reach my monitoring host. Just…
Juicy
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10
votes
1 answer
Cisco IPv6 BNG Radius Attributes
I am trying to push out IPv6 unnumbered to an interface via radius. I am trying to do it in a similar fashion to how you would for IPv4:
Cisco-AVPair += "ip:vrf-id=vrf-name",
Cisco-AVPair += "ip:ip-unnumbered=Loopback301",
I am trying to assign a…
Firebirdnz
- 661
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10
votes
1 answer
Using RADIUS to restrict SSID on Cisco Aironet
I would like to use my RADIUS server to restrict access to configured SSID on a per user basis.
According to the documentation linked above i add the following attribute to a test user:
ospite-5vh Cisco-AVPair += "ssid=Interactive_Ospiti"
So,…
Marco Marzetti
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10
votes
1 answer
Is ATM still used as a transport protocol?
In addition to reading new material, I enjoy reading older networking books in attempt to see where we've come from and possibly where we're going. Currently, I'm reading a book called Cisco LAN switching, which was published in 1999 as part of the…
WaxTrax
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10
votes
4 answers
how to get scp via snmp to work with cisco routers?
I have a lab setup where I'm trying to use SCP via SNMP to a cisco router.I found some online documentation such as: http://ccie20728.wordpress.com/2008/05/20/get-the-cisco-configuration-over-snmp/
Here's my high level setup. On router:
R1(config)#…
user1609
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10
votes
3 answers
Why is my UDP broadcast wireless communication capped at 1 MB/s?
I am trying to implement Network Coding over a meshed network. Therefore I need to send packets to several destinations, this is way I am using Broadcast packets. But I can not understand why this is capped at ~990KBs.
Is there some configuration to…
Vladimir Leiv
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10
votes
3 answers
Inbound BGP load-balancing from same ISP router
I have two BGP routers for DIA with an issue with one provider in that the two links to this provider land on the same SP router. My ethernet handoffs via two separate MetroE links from another provider on behalf on my main provider as the one…
generalnetworkerror
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10
votes
2 answers
Why PPTP, L2TP, PPPOE are in OSI Layer2?
PPTP, L2TP, PPPOE - these are tunneling protocols. And they are Data link Layer protocols. Why?
As I understood, Layer2 protocols work only in same subnet. They don't use IP addresses and cannot be routed. They operate only with MAC addresses.…
Алдар
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10
votes
4 answers
Redundancy between router and servers
In the past, I was using a NetGear GS724T between my router and my servers. Unfortunatly the switch suddenly died.
Now I've changed it for a GS748T and also bought one more and I am wondering how I could achieve a redundancy using these two…
Alexandre Lavoie
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10
votes
2 answers
Why does the MTU need to match on interior link state routing protocols like EIGRP and OSPF?
If one tries to configure the neighbor adjacencys without matching MTU, The routers fail to become neighbors. I assume this is to protect the routing protocol from it self but I don't understand what it is saving itself from? What would(Could)…
Pete
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