New answers tagged

0 votes
Accepted

Extreme 210 fiber port not connecting

This is going to seem dumb, but I finally got this working. I had to go to the other end of the fiber cable. I found that it was the port on the other switch, also an Extreme 210 (210-24p-GE2), was in ...
user avatar
  • 113
0 votes

Simple IPv6 Global Unicast question

Remember that four bits are used for each hexadecimal digit. 0010 and 0011 are the bits for the first hexadecimal digit in /3, and the correspond to 2 and 3 in hexadecimal. The first three bits are ...
user avatar
  • 92.8k
3 votes

Simple IPv6 Global Unicast question

Left most 001 are fixed, this means the left most nibble can be: 0010 = 0x2 0011 = 0x3 The 4th left most bit is not fixed.
user avatar
  • 1,402
0 votes

How to use IP pool

You are given only one public IP address by your Internet service provider, ISP. This is common. Assign that public IP address to the Internet facing interface on your router/firewall and use Port ...
user avatar
0 votes

How to use IP pool

103.15.xx.xx/30 can mean two different things: A subnet with four IP addresses, two of which usable, but one is used by the upstream router and one address is free for you to use. Likely, 103.15.xx....
user avatar
  • 69.5k
1 vote

Do PoE lighting systems require a separate network from other PoE systems?

PoE switches are often responsible for powering telephones which are expected to work in the event of a power outage. This is achieved by backup power for the centralized switch farm(s). Typically ...
user avatar
0 votes

Why is a PoE circuit limited to 328 feet?

PoE requires copper wire. Otherwise, longer reaching spans of fiber optic cable would normally be used along with a media converter + PoE power injector at the far end. Another solution to distance ...
user avatar
3 votes

Why is a PoE circuit limited to 328 feet?

IEEE PoE is an option for IEEE 802.3 twisted-pair Ethernet which is generally limited to 100m in total - up to 90m of rigid, solid-core cable and up to 10m of flexible, stranded cable. If you use ...
user avatar
  • 69.5k
1 vote

Do PoE lighting systems require a separate network from other PoE systems?

If I have a managed switch with IP cameras, could I add (generic) PoE lighting on the same network or would I need to create a logical network to keep the two systems from seeing one another? While ...
user avatar
  • 69.5k
1 vote

Extreme 210 fiber port not connecting

With Link Status down and Admin Mode enabled, I'd say the cable is either not fitted correctly or damaged. I'd try reseating the SFP module and replugging both ends. Check the cable for excessive ...
user avatar
  • 69.5k
1 vote

Why should I use vlans instead of subnets?

VLAN's and subnets are not competing solutions to the same problem. They exist independent of one another. A local area network is one or more switches linked together. VLAN's are enabled by software ...
user avatar
0 votes

Why should I use vlans instead of subnets?

TLDR; VLANs reduce unneeded local broadcast traffic and can also reduce the ACL control points if paired with a logical IP range partitioning, besides reducing the network vulnerabilities exposure. ...
user avatar
  • 19
0 votes

Why iBGP speaker should not modify next hop address?

One reason, I can think of, is when you have two exit points from your local AS. In this case setting next-hop-self on one of the boundary routers will change BGP's path selection to only use this ...
user avatar
  • 1,402
2 votes
Accepted

Why should I use vlans instead of subnets?

Why should I use vlans instead of subnets? VLANs cannot replace IP subnets. But they can structure your network - for scalability, resilience, security, or some other reason. Since hosts in different ...
user avatar
  • 69.5k
2 votes

Why should I use vlans instead of subnets?

VLANs are not a substitute for subnets, they are a substitute for physical LANs: actual wired connections. You use them in addition to subnetting, router ACLs, etc., not instead of. So, you could have ...
user avatar
  • 1,448
2 votes

Why should I use vlans instead of subnets?

Broadcast domain is a layer 2 network, while subnet is a layer 3 network. When you understand the purposes an differences between them, read on. VLAN is a feature of Ethernet switch which separates ...
user avatar
  • 391
0 votes

Why is Packet Size Limited?

I believe the crucial detail in this discussion is that network is unreliabe. There is no guarantee that data, sent over the network, actually gets delivered as it is. This means that network nodes (...
user avatar
  • 1,290
2 votes

How does ARP work, when the host with known MAC address is moved to another subnet

You're mixing up your ethernet layer and your IP layer. Remember that ARP is a protocol where a host broadcasts "who has IP address x?" on a given ethernet, and (usually) receives an answer ...
user avatar
  • 15.9k
1 vote

EEM Script Using Variables

Thanks for your input Jesse! After some trial and error, this is what I ended up using. Works like a charm! event manager applet TUNNEL-FIX authorization bypass event syslog pattern ".Tunnel([0-9]...
user avatar
1 vote

In an SDN (OpenFlow), are all switches directly connected to controller?

The quoted answer is not quite correct. Switches have a logical connection to the controller, but not a physical one -- at least not in a network of any size. Openflow protocol uses TCP/IP (port 6653)...
user avatar
  • 62k
1 vote

How does ARP work, when the host with known MAC address is moved to another subnet

Since you have a router, or 3 routers, between PC0 and PC1, PC0 would not learn PC1's mac address at all. Most likely your PC0 would be configured to send all packets to its default gateway - the ...
user avatar
  • 1,290
3 votes

How does ARP work, when the host with known MAC address is moved to another subnet

It seems that you have a conceptual problem, so I'm going to take it back to basics: Ethernet can be thought of as a bus, which the orginal thickwire Ethernet more or less was. Each node on the ...
user avatar
  • 1,448
4 votes

How does ARP work, when the host with known MAC address is moved to another subnet

The IPv4 address of the moved device would change, so it would be a completely different ARP table entry. Remember, the ARP table is indexed by the IPv4 address, so trying to communicate would result ...
user avatar
  • 92.8k
-1 votes

Are WAN and "backbone" same?

Actually, most of actual backbones are WANs, but not all WANs are backbones, WANs are wide networks, and those include in most of the cases, to users, while backbones networks are the core of a ...
user avatar
  • 1
2 votes
Accepted

Are WAN and "backbone" same?

Historically, LAN and WAN stood for vastly different technologies. Since nearly anything nowadays uses former LAN technology (Ethernet), that distinction has all but vanished. Today, the terms depend ...
user avatar
  • 69.5k
2 votes

Are WAN and "backbone" same?

Backbone is a general term that can only be understood in context. So in some cases a backbone could be a WAN, but in other cases, no. Backbone refers more to the topological structure, where it ...
user avatar
  • 62k

Top 50 recent answers are included