4 votes
Accepted

How do ISPs ensure that the IP block that is being advertised to them is valid?

As Ron has said, "very little". Some will do no validation at all. Others may only require a piece of paper - a signed "letter of authority". Ultimately, they have little option ...
Ricky's user avatar
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4 votes

How do ISPs ensure that the IP block that is being advertised to them is valid?

You may be surprised to learn that there is very little validation, and it varies wildly from one ISP to another. RFC 7454 describes best practices for filtering prefixes received by peers. Lots of ...
Ron Trunk's user avatar
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4 votes
Accepted

Interior vs Exterior Gateway Protocols

In practice, there is only one EGP in use today, and that is BGPv4. OSPF and EIGRP are the most common IGPs. RIP is essentially obsolete. Can a company private network be considered as an ...
Ron Trunk's user avatar
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3 votes
Accepted

Does ARP play any role when we try to access a website?

Your PC only sends an ARP request for hosts on the local network. For all destinations on other networks, the PC sends the packet to the default gateway. Your PC will send an ARP request for the ...
Ron Trunk's user avatar
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2 votes

Connect site-to-site private networks

I will assume that Router A and Router B have each a public IP address and that they run an IPSec tunnel to each other to/from that public address. You'll need to (reciprocally) make sure that Router ...
Marc 'netztier' Luethi's user avatar
2 votes

Geolocation specific ASN

ASNs aren’t bound to a specific location, so what you’re asking is impossible to answer in general. Some large networks may use an ASN for a specific region, but if that’s the case you can only find ...
Teun Vink's user avatar
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1 vote
Accepted

Communicating Between Two Devices When One Lacks Internet Access

For device A to talk with device B, there must be a communications channel between them. The Internet is one such channel -- the most common, and easiest. That could also be a direct ethernet cable, ...
Ricky's user avatar
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1 vote

Does an official list of tier 1 ISPs exist?

There is no standard defining 'tier 1'. So no, there's no formal list. There are many slightly different interpretations on what a tier 1 is.
Teun Vink's user avatar
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1 vote

Does ARP play any role when we try to access a website?

ARP is only ever used to resolve local IP addresses to their corresponding MAC address. Any MAC addresses used outside your local network are useless and generally unknown. When communicating with ...
Zac67's user avatar
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