CCNP BSCI Notes
30 Mar 2008
Chapter 1: Network Design
Full mesh formula: n(n-1)/2
Example: To create a mesh between 8 nodes, 8 * (8-1) / 2 = 28; 28 links are needed.
Design concepts
Legacy Hierarchical Design Model
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Core - fast L2-switched backbone
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Distribution - L3 switches
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Access - dense L2 switches
This failed to address issues such as redundancy, Internet and remote access, and locating services.
Switch block design was introduced to add redundancy; this included redundant core and distribution switches and links per switch block.
Enterprise Composite Network Model
This new model was developed to address modern design considerations.
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Enterprise campus
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Campus backbone (previously the "core")
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Building distribution (previously "distribution")
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Building access (previously "access")
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Management
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Server farm (for internal enterprise services)
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Enterprise edge
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E-commerce
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Internet connectivity
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Remote access
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WAN (internal links)
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Service provider edge
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ISP
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PSTN
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Frame relay, ATM, PPP for private connectivity
Intelligent Information Network (IIN)
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Phase 1: Integrated transport - the shift toward the ECN model
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Phase 2: Integrated services - service virtualization (disassociation of services from individual machines)
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Phase 3: Integrated applications - recognizing and combining high-layer traffic properties (for example, Network Access Control)
Services-Oriented Network Architecture (SONA)
SONA is the application of IIN ideas to enterprise networks.
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Network infrastructure (IIN phase 1)
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Interactive services (IIN phase 2)
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Application (IIN phase 3)
Routing protocols
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Distance vector - a router will only exchange routes with a directly connected neighbor
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Link-state - a router advertises a list of all its neighbors and its neighbors' networks; routers run SPF to determine the best path
Just a quick note -
"Registries receive a range (typically a /23) within 2001::/16"
... this is now /12 assignments from within the 2000::/3 range ...
You've wrote
"Uses Reliable Transport Protocol (RTP, Cisco proprietary) for some traffic (updates, queries, and replies) "
Though the protocol used in EIGRP is indeed reliable due the ACK packets, I believe the protocol's name is Real-Time Protocol.
Another thing:
"Feasible distance - Advertised distance + cost get to that neighbor "
Though it is somewhat correct, AFAIK it's not a simple equation, as the formula uses the minimum bandwidth of the path, and the summa of the delays. Meaning though the cost to a loopback of a neighbor's loopback address (which should be the cost of the actual link), shall not be the same as the difference between the feasible distance and advertised distance for a remote network.
Gabor,
The RTP used with EIGRP is actually Reliable Transport Protocol. From the docs: "Reliable Transport Protocol (RTP) is responsible for guaranteed, ordered delivery of EIGRP packets to all neighbors." This essentially amounts to the use of sequence and acknowledgment numbers within EIGRP.
Well, then we shall note Cisco press they are either mistaken, or i couldn't quite see their point.
In Cisco press's "CCNP BSCI official exam certification guide, fourth edition" page 48 they indeed say "Reliable Transport Protocol", on page 56 (quote) "EIGRP uses both multicast and unicast addressing. Some packets are sent reliably using Real-Time Protocol (RTP), a Cisco proprietary protocol that oversees the communication of EIGRP packets."
When I posted my last comment have doublechecked in the above book, as I wasn't sure in myself, however it seems i was not thorough enough.
From above "K values are used to distribute weight to different path aspects: * bandwidth - Defined as 107kbps divided by the speed of the slowest link in the path"
Does anyone read that 107kbps as I did? I think they mean 10^7, or 10,000,000
Thanks!!!
(Edit: Good catch! You are correct, the correct reference value is 10,000,000 Kbps (or 10 Gbps). I had blindly duplicated an error in the book. All fixed now, thanks for pointing it out. -stretch)
@Gabor: I am reading the Cisco BSCI and just ran into Cisco referencing RTP - Real Time Protocol.
On page 473 in Chapter 17 - Multicasting - it states "For multimedia traffic, ordering is handled by the Real Time Protocol (RTP)."
So this could be where you confused it with the Realiable Transport Protocol used with EIGRP.
Dear Sir:
I like your blog very much, it is simple and clear and graceful.
I hope you can focus on a topic - Is DHCP message about DHCPOFFER/DHCPACK unicast or broadcast message? I think it will be very useful to make it clear for all beginners.
Because Microsoft said all of them are broadcast, but in Cisco Documents said they are unicast...
Just a quick note - "Registries receive a range (typically a /23) within 2001::/16"
... this is now /12 assignments from within the 2000::/3 range ...
You've wrote "Uses Reliable Transport Protocol (RTP, Cisco proprietary) for some traffic (updates, queries, and replies) " Though the protocol used in EIGRP is indeed reliable due the ACK packets, I believe the protocol's name is Real-Time Protocol.
Another thing: "Feasible distance - Advertised distance + cost get to that neighbor " Though it is somewhat correct, AFAIK it's not a simple equation, as the formula uses the minimum bandwidth of the path, and the summa of the delays. Meaning though the cost to a loopback of a neighbor's loopback address (which should be the cost of the actual link), shall not be the same as the difference between the feasible distance and advertised distance for a remote network.
Gabor,
The RTP used with EIGRP is actually Reliable Transport Protocol. From the docs: "Reliable Transport Protocol (RTP) is responsible for guaranteed, ordered delivery of EIGRP packets to all neighbors." This essentially amounts to the use of sequence and acknowledgment numbers within EIGRP.
Well, then we shall note Cisco press they are either mistaken, or i couldn't quite see their point. In Cisco press's "CCNP BSCI official exam certification guide, fourth edition" page 48 they indeed say "Reliable Transport Protocol", on page 56 (quote) "EIGRP uses both multicast and unicast addressing. Some packets are sent reliably using Real-Time Protocol (RTP), a Cisco proprietary protocol that oversees the communication of EIGRP packets."
When I posted my last comment have doublechecked in the above book, as I wasn't sure in myself, however it seems i was not thorough enough.
From above "K values are used to distribute weight to different path aspects: * bandwidth - Defined as 107kbps divided by the speed of the slowest link in the path" Does anyone read that 107kbps as I did? I think they mean 10^7, or 10,000,000 Thanks!!!
(Edit: Good catch! You are correct, the correct reference value is 10,000,000 Kbps (or 10 Gbps). I had blindly duplicated an error in the book. All fixed now, thanks for pointing it out. -stretch)
@Gabor: I am reading the Cisco BSCI and just ran into Cisco referencing RTP - Real Time Protocol.
On page 473 in Chapter 17 - Multicasting - it states "For multimedia traffic, ordering is handled by the Real Time Protocol (RTP)."
So this could be where you confused it with the Realiable Transport Protocol used with EIGRP.
Dear Sir:
I like your blog very much, it is simple and clear and graceful.
I hope you can focus on a topic - Is DHCP message about DHCPOFFER/DHCPACK unicast or broadcast message? I think it will be very useful to make it clear for all beginners.
Because Microsoft said all of them are broadcast, but in Cisco Documents said they are unicast...