6
votes
Accepted
What is the minimum number of IP addresses an autonomous system can have?
Is it possible to have an autonomous system with just one IP address?
Theoretically, yes, but the ISPs will not advertise any IPv4 prefix larger than /24 or IPv6 prefix larger than /48 on the public ...
- 100k
6
votes
Accepted
Differences between Enterprise internet connections with the same nominal bandwidth
A few things you should look at:
is the bandwidth symmetrical? I.E. do you get 150Mbps download AND 150Mbps upload?
is the bandwidth guaranteed?
what are the S.L.A. (Service Level Agreement)? In case ...
- 19.8k
5
votes
Accepted
Internet structure and ISP networks in detail
You're mixing up a couple of things. Also be aware that Internet structures are very different in different countries.
A DSLAM is part of the Digital Subscriber Line technology, delivering Internet ...
- 16.3k
5
votes
Is a transit agreement with a tier 1 provider sufficient to connect to the entire internet?
Hopefully.
A tier 1 provider relies entirely on sending data (and routes for incoming data) to customers and peers, they have no upstream providers. That means if you rely on a single tier 1 for ...
- 13.6k
4
votes
Accepted
Is a transit agreement with a tier 1 provider sufficient to connect to the entire internet?
Yes. In fact an agreement with any tier provider is sufficient. The difference is reliability, bandwidth, and cost.
- 67.9k
4
votes
What is the minimum number of IP addresses an autonomous system can have?
The longest prefix/smallest subnet for IPv4 that can be announced on public BGP is /24 = 256 IP addresses.
Note that each announcement likely ends up in the global routing table. Limiting the amount ...
- 86.4k
4
votes
Accepted
Fiber Type and transceiver model required
You don't need to be concerned with how any ISP runs their network. All that matters to you is what they hand-off. ISP A gave you MM/10G-SR; ISP B is giving you SM/10G-LR. You will need new fiber ...
- 32.4k
4
votes
Accepted
WAN lines types - understanding leased line/circuit
A real leased line, could be performed with TDM on a line with for example SDH, TDH or SONET with a CSU/DSU on the customer site (a layer 1 leased line?)
This depends - usually a (rare) leased ...
- 86.4k
4
votes
Service Provider inbound routing problems before using communities
The problem of manipulating paths in BGP is that your peer ASes are free to ignore what your AS wants. There are many steps to deciding which routes are preferred in BGP. You can try to influence your ...
- 100k
2
votes
Frame tag decision based on switch port TPID (EtherType)
The first 6 bytes of an ethernet frame are the destination MAC address, the next 6 bytes are the source MAC address. The next two bytes, 13th and 14th bytes, are the payload length (<= 1500) or the ...
- 100k
2
votes
Internet structure and ISP networks in detail
Welcome to Network Engineering! Yes, you have the basic concept correct. In step 3, ISP_A will determine that the path to the destination address goes through ISP_C, so it will forward the datagram ...
- 67.9k
1
vote
Are the terms 'service endpoint' and 'service access point' synonymous?
Service Access Point (SAP)
A SAP is a logical entity that serves as the customer's point of access into a service. Each subscriber service is configured with at least one SAP. A SAP can only be ...
- 121
1
vote
Accepted
2 AS in the same box JunOS
There are several ways to do this.
Logical Systems (LSYS)
Logical Systems are a means of segmenting your Junos router into multiple logical systems, which have separate configurations, routing ...
- 5,571
1
vote
2 AS in the same box JunOS
The best way is to ask the smaller ISP to modify their configuration to accept your AS number.
- 67.9k
1
vote
How is traceroute able to display hostnames?
Traceroute does use Reverse DNS lookup or reverse DNS resolution (rDNS). Querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address. The process of ...
- 1,587
1
vote
Accepted
Assign a new public and static IP to a router behind my main router
From what I can gather, you're looking for another /32 of publicly routable space. If so, you will need to contact your provider or even change providers as many residential providers may not be able ...
- 1,317
1
vote
Physical interface as switch port and VLAN interface as layer 3
Not sure what you're aiming at, but the main point is scalability: you bind your L3 interface to a VLAN. A VLAN is a virtual entity as large as the L2 segment - not even limited to a single switch. ...
- 86.4k
1
vote
Accepted
How to use dynamic NAT to allow access from customer RFC1918 subnets for access to Internet and LAN?
I believe to have grasped this from your problem description:
new SP delivers a WAN service which happens to have an internet exit "somewhere upstream".
CPE-CE link has to be a publicIPv4 /30, as ...
- 8,846
1
vote
Accepted
VoIP Provider and Phone Number Routing Questions
DIDs are assigned by the telcos which own them. A VoIP provider buys a block of DIDs from the telcos it uses where its VoIP network interfaces with the POTS network.
Your cell call travels from the ...
- 100k
Only top scored, non community-wiki answers of a minimum length are eligible