BackBPG Routing
Hello,
Saar here, resident engineer at Myriad Supply. Today I’ll be talking about BGP Routing.
BGP…you probably hear that word being thrown around. What is it and how can it help you? First, take a look at this cheat-sheet. The second item will give you a brief explanation on BGP and its uses.
Cheat Sheet
The first item is the port speed from 10/100/1000 to 100Gbps. The second one is how many FULL tables we recommend.
For the 1 GigE you have the best horse is the older 7200
For the 1 GigE you can also invest in the 6500/7600 with XL
For the 10 GigE you have 2 out of 3 horses with hefty discounts on Brocade and Juniper.
For the 10 GigE you can also get the older 6500 with XL and 6704/6708 line cards.
For the 40 GigE. You can use the 6500 with SUP-2T or look at our Juniper/ Brocade Chassis offerings. Again 3 out of the 4 horses are available to you.
Allow me to explain:
Let’s say you’re sitting in the office and you want to email Mr. Borat Sagdiyev. There are many ways of reaching Borat, as many ways as there are countries and ISPs in the world. The reason for that is that NOBODY owns the internet. It’s basically made up of thousands of internet providers who will link to each other (which is why they say the internet should be capable of surviving a nuclear attack). For example, from NY, you can send data across the country through the Pacific pipeline to Japan and reach Borat. In summary, the internet is a large collection of ISPs working together sharing links so they can route your traffic to Borat.
In order to work together, the ISPs need a protocol that will allow them to update all the addresses of the world and any changes. This protocol is Border Gateway Protocol, BGP.
The idea is simple- Each enterprise company or ISP can apply for something called an AS number.
http://thyme.apnic.net/rviews/data-AS20net-RIPE
ASN No of nets /20 equiv Description
25534 156 1 Intelsoft Kazakstan AS
As you can see, the ISP in Kazakstan where Borat lives applied for ASN 25534. So basically, each ISP or Enterprise company canapply for an ASN. As you also know, in order to talk to other devices in the world, your PC needs to have a real PUBLIC IP address (you can see yours by going to http://www.ipchicken.com/).
An ISP buys an AS number, and then publishes all of the network it controls publicly using the AS.
Origin AS Network
3215 2.0.0.0/16
3215 2.0.0.0/16
3257 2.16.6.0/23
3257 2.16.6.0/23
http://thyme.apnic.net/rviews/data-AS-RIPE
To better explain in English.
in the BGP Table you will see:
12.0.0.0 go to 55002
14.0.0.0 go to 55002
23.0.0.0 go to 55003
24.0.0.0 go to 55003
25.0.0.0 go to 55003
26.0.0.0 go to 55003
190.0.0.0 go to 30000 {which is the Borat one}
Basically a long table with routes.
The table currently holds 350,000 lines or records, soo to connect to a single Provider and receive a FULL TABLE your router will need the capacity to handle 350,000 lines.
Let’s say I’m a company and I use TWC business. Someone at TWC management was playing with stock options on derivative values of badwidth firecasting and lying on the yearly reports (ENRON anyone?) and the company collapses. As it collapses, my internet dies, and I lose money because the website is down since my ISP is down. Or, let’s say another storm like Hurricane Sandy hits New York and the TWC ISP hub and routers all get washed away with some sea water. Again, my business will lose money.
In order to protect myself against my ISP failing, I can connect to a second ISP:
So now my router will be getting 2 full tables: 350,000 routes from the ISP switch numbered 55003 and 350,000 routes from the ISP switchnumbered 55004. And now my router needs the capacity to handle 700,000 lines.
What happens with 3 providers with full tables, which a data center might connect to? Well, 1,050,000 lines is what happens.
Now let’s have a look at how that affects buying a router. You might wonder if you can use the 3750 with a BGP license to get a full table. The answer is yes, but the 3750 can only handle 11,000 routers.
Since you need 350,000 routes in order to have a full table, the 3750 will not be able to handle it. The same applies to the Juniper switches and all others. All switches aren’t capable of getting a full table, so you can disqualify almost all switches.
So what can you get?
The Cisco3845, MEM3800-512U1024D. Can handle 1 FULL table (Cisco 3945 or 3945E are similar)
Generally, if you’re looking for a good deal on pre-owned, Cisco7200 with NPE-G1 and NPE-G2 with maximum memory can handle the 2 full tables.
The disadvantage of the 38 series, the 39 series, and the 7200, however, is that they do not support 10GigE ports.
If you do want BGP and 10 GigE, you ca start looking at the Cisco ASR:
The ASR is new and harder to find, and also needs a Line Card (SPA) with the 10 Gig ports.
At this level, we can leverage our partners, like Brocade, which offers a router called a CER.
The CER is like a high-end switch, jacked up and injected with brains and memory, up to 1,500,000 IPv4 uniast routes in FIB: http://www.brocade.com/downloads/documents/data_sheets/product_data_sheets/NetIron_CER_2000_DS.pdf
Using our rule of thumb, 1,500,000 means it’s good for 2, 3, or 4 full tables. It also has 2 or 4 10GigE ports depending on the model.
You may also be interested in the Juniper MX Series Router, which can hold 2,000,000 routes, and can grow from 2, 4, 6, or 8 ports depending on what you order.
At higher levels, if you need more ports, you may want to look at the 6500/7600 with an SUP3BXL, SUP3CXL, or SUP2TXL.
The reason for the XL, which stands for Xtra Large, memory table is that it can hold more routes- Namely, 1,000,000 routes.
If you need more than that, take a look at the MX240 or the MX480.
To request a quote or for more information, be sure to check out http://www.myriadsupply.com/.
Saar Harel is a resident Engineer at Myriad Supply, and has been in the Networking Field for over 20 years. You can check out his Google+ and ask him questions!
