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How to Peer with Route Servers

Route servers do propagate prefixes from one peer to all their other peers. At least, that's how route servers typically operate today.
In figure 1, the networks do not peer directly, but all maintain BGP sessions with AS 25, the route server. Note that each AS has allprefixes, and the AS path is a hop longer because AS 25 appears in it.

Figure 1: BGP sessions towards a route server: http://d39z3tvn9akifj.cloudfront.net/ccie/wp-content/uploads/2015/02/bgp-sessions-1024x499.png

Under normal circumstances, the traffic would now flow through the route server, making running a route server on a big internet exchange a non-starter. However, BGP is smart enough to recognize that all the route server peers are connected to the same subnet (the internet exchange peering LAN). So unlike it does under other circumstances, BGP doesn't update the next hop address. This means that when AS 456 gets the route to 1.2.3.0/24 from the route server, the next hop address isn't the route server's address, but the AS 123 router's address. As such, packets don't flow through the route server, but rather, are directly delivered to the right AS, as shown in figure 2.

Figure 2: Traffic flow when peering with a route server: http://d39z3tvn9akifj.cloudfront.net/ccie/wp-content/uploads/2015/02/route-server-1024x502.png

However, there are also some networks that have an open peering policy and will peer directly with anyone, but don't peer with route servers, because that way they don't control their peerings. For instance, when there is an issue with a peer, it's useful to be able to temporarily shut down the BGP session with that peer. If the peering happens through a route server, you'll either have to wait for the route server operator to take action or shut down the BGP session towards the route server and impact lots of other peers, too.

Most networks prefer to peer through the route servers exclusively when possible, while other networks like to add direct peering in addition to the route server peering. The argument in favor of a route server only policy is that it keeps the amount of work and the number of BGP sessions to a minimum. On the other hand, adding direct peering has the advantage that if there's an issue with the route server peering, there's still the direct peering.

The BGP session towards a route server is configured exactly the same as any other BGP session used for peering. The route server itself can also be a standard BGP router, or a Unix (-like) system running BGP software. The route server configured to allow prefixes from each peer to propagate to other peers. A regular router performing route server duties will include its own AS in the AS path for prefixes it propagates, as shown in figures 2 and 3. This makes paths learned through the route server a hop longer, so paths learned through direct peering will be preferred. However, it's not uncommon for route servers to be set up to leave out their own AS number in the AS path propagated to peers, so there's no impact to AS path length.

Source: Peering with Route Servers - BGP Case Study

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wht does peer to peer mean


A peer is like a workstation which contributes it's resource (hard disk space,speed,Bandwidth etc.) without the need of central coordination (servers).They are both suppliers and consumers of the resources.

In simple words if you have noticed P2P clients like uTorrents,Bittorrents and many other and you want to download a file...you first download the torrent file--run it--and you start downloading it in 'parts'(consumer) from different people who already have downloaded the files and also you will see that you are using some of your bandwidth in uploading too (supplier) which means other people are also downloading from your workstation.You can even stop someone from downloading the file from your end.
This is what peer-to-peer is all about.

Dec 13, 2009 | Computers & Internet

1 Answer

2002 Cadillac ignition turn


  • A network is a group of computers (often called nodes or hosts) that can share information through their interconnections. A network is made up of the following components:

    Computer systems (nodes or hosts)
    Transmission media--a path for electrical signals between devices
    Network interfaces--devices that send and receive electrical signals
    Protocols--rules or standards that describe how hosts communicate and exchange data
    Despite the costs of implementation and maintenance, networks actually save organizations money by allowing them to:

    Consolidate (centralize) data storage
    Share peripheral devices like printers
    Increase internal and external communications
    Increase productivity and collaboration
    There are several ways to classify networks. The following table lists several ways to describe a network.

    Peer-to-Peer In a peer to peer network, the hosts provide and consume network services, and each host has the same operating system. Advantages of peer to peer networks include:
    Easy implementation
    Inexpensive
    Disadvantages of peer to peer networks include:
    Difficult to expand (not scalable)
    Difficult to support
    Lack centralized control
    No centralized storage

    Client/Server In a client/server network, hosts have specific roles. For example, some hosts are assigned server roles which allows them to provide network resources to other hosts. Other hosts are assigned client roles which allows them to consume network resources. Unlike peer to peer networks, hosts in a client/server network have different operating systems. Advantages of client/server networks include:
    Easily expanded (scalable)
    Easy support
    Centralized services
    Easy to backup
    Disadvantages of client/server networks include:
    Server operating systems are expensive
    Requires extensive advanced planning

    Geography and Size
    Local Area Network (LAN) LANs reside in a small geographic area, like in an office. A series of connected LANs, or a LAN connected across several buildings or offices, is called an internetwork.
    Wide Area Network (WAN) A WAN is a group of LANs that are geographically isolated but connected to form a large internetwork. When implementing a WAN, remember to provide local access to user resources to prevent a high rate of WAN traffic.
    Participation
    Private A LAN or WAN for private individual or group use which may or may not be secure. Examples include home and organization (small business, corporate, institute, government) networks. Intranets and extranets, although related to the Internet, are private networks. Both an extranet and intranet are tightly controlled, and made available only to select organizations. An extranet is made available to the public and an intranet is made available internally.
    Public A large collection of unrelated computers, with each node on the network having a unique address. The Internet, for example, is a public network. Because computers are unrelated and many companies and individuals share the same communication media, the public network is by nature insecure.
    Signalling
    Baseband Baseband signalling allows one signal at a time on the network medium (cabling).
    Broadband Broadband signalling divides the network medium into multiple channels, allowing several signals to traverse the medium at the same time.





Jul 08, 2009 | 1995 Cadillac Seville

1 Answer

C13 ...same problem!!!!


A network is a group of computers (often called nodes or hosts) that can share information through their interconnections. A network is made up of the following components:

Computer systems (nodes or hosts)
Transmission media--a path for electrical signals between devices
Network interfaces--devices that send and receive electrical signals
Protocols--rules or standards that describe how hosts communicate and exchange data
Despite the costs of implementation and maintenance, networks actually save organizations money by allowing them to:

Consolidate (centralize) data storage
Share peripheral devices like printers
Increase internal and external communications
Increase productivity and collaboration
There are several ways to classify networks. The following table lists several ways to describe a network.

Peer-to-Peer In a peer to peer network, the hosts provide and consume network services, and each host has the same operating system. Advantages of peer to peer networks include:
Easy implementation
Inexpensive
Disadvantages of peer to peer networks include:
Difficult to expand (not scalable)
Difficult to support
Lack centralized control
No centralized storage

Client/Server In a client/server network, hosts have specific roles. For example, some hosts are assigned server roles which allows them to provide network resources to other hosts. Other hosts are assigned client roles which allows them to consume network resources. Unlike peer to peer networks, hosts in a client/server network have different operating systems. Advantages of client/server networks include:
Easily expanded (scalable)
Easy support
Centralized services
Easy to backup
Disadvantages of client/server networks include:
Server operating systems are expensive
Requires extensive advanced planning

Geography and Size
Local Area Network (LAN) LANs reside in a small geographic area, like in an office. A series of connected LANs, or a LAN connected across several buildings or offices, is called an internetwork.
Wide Area Network (WAN) A WAN is a group of LANs that are geographically isolated but connected to form a large internetwork. When implementing a WAN, remember to provide local access to user resources to prevent a high rate of WAN traffic.
Participation
Private A LAN or WAN for private individual or group use which may or may not be secure. Examples include home and organization (small business, corporate, institute, government) networks. Intranets and extranets, although related to the Internet, are private networks. Both an extranet and intranet are tightly controlled, and made available only to select organizations. An extranet is made available to the public and an intranet is made available internally.
Public A large collection of unrelated computers, with each node on the network having a unique address. The Internet, for example, is a public network. Because computers are unrelated and many companies and individuals share the same communication media, the public network is by nature insecure.
Signalling
Baseband Baseband signalling allows one signal at a time on the network medium (cabling).
Broadband Broadband signalling divides the network medium into multiple channels, allowing several signals to traverse the medium at the same time.

Jul 08, 2009 | Sony MDS-JE480 Mini Disc Player

2 Answers

1991 SAAB Turbo dies when running as I approach intersections


Assuming this is a 900. Check the ignition lead from the dizzy to the igition pack. I once had a similar problem, and also check for ANY air pipe leaks. These cars are especially sensitive to air leaks. Look especially at the manifold pipes. Also, make sure tha intercooler pipe is secure. Is there any excessive smoking through the tailpipe?

May 10, 2009 | 1991 Saab 900

1 Answer

Same Problem Again - Mega Raid.... Unknown Error


Hi

The title of your post suggests that you have "Maga RAID" errors. Maga RAID messages would be in line with issues on the LSI PERC sub-system.

However, the extract posted in your suggests network problems.

Any number of physical to driver and configuration issues can result in network problems.

Try the basic checks;
1. Change or try a known patch cable
2. Run "ping" test to a known good system connected to same network switch or direct connect with a "cross-over" cable and check for dropped connections.
3. Is the NIC and switch set to Auto-Negotiation or static at 10, 100 or 1000Mbps speed
4. Can you try another switch
5. Check and load correct or latest manufacture's drivers

Reply with more info.

Mike

Jan 23, 2008 | Dell PowerEdge 1800 Server

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