## 6 Comparison of the BSI and NIST Guides
The content depth score of the NIST guide is on average 0.22 higher than the depth of the BSI guide and 0.26 higher in the total results. These results imply that the NIST guide is on average and in total at least one level better concerning depth with respect to the levels definitions of Section 3.2 (missing, very low, low, medium, high, very high). In total, depth of the BSI guide is very low at 0.17 and the NIST guide is a little above medium, with a value of 0.43. This shows that the NIST guide is generally much more detailed and provides more explanations and examples. There is only one subcategory where the BSI guide exceeds the NIST guide in depth which is _Routing Protocols_. However, the BSI value is only 0.04 higher and thus both are still close together. There are in total three subcategories where both are less than 0.1 apart from each other and another three within 0.12 difference. On the other hand, there are also six subcategories where both guides differ more than 0.3 points in depth. This group is lead by _DNS Security Issues_, with a difference of 0.44 in depth and followed by _IKEv2_, with a 0.4 points difference. Figure 8 shows the average depth of covered RFCs for both guides, which is the ratio of aggregated depth scores to the number of actually covered RFCs. From this perspective it becomes clear that both guides have on average a low to medium depth for covered RFCs. Interestingly, the depth of RFCs that are covered is slightly higher in the BSI guide than it is in the NIST guide. This is because the NIST guide often only mentions relevant RFCs without going into detail while the BSI guide only covers RFCs that it also explains at least to some extent. There are some subcategories where differences become particularly evident. Within the category _Specification and Address Format_, the subcategory _Mobile IPv6_ stands out the most. This subcategory  
Figure 8: Average depth of covered RFCs in total. is barely covered by the BSI guide (0.14), but received a lot more coverage from the NIST guide (0.9). Nevertheless, both guides did not cover this subcategory much in terms of depth. The NIST guide achieved a depth of 0.42. This is 0.23 higher than the value of the BSI guide. The BSI guide does not yet consider _Mobile IPv6_ as an important topic for an initial deployment of IPV6. The NIST guide, however, does provide more coverage of the topic as shown by the completeness and depth values. The coverage by the BSI guide can be considered too low when looking at the importance rating of 5.76. While this value is not high, it still indicates the need for at least medium coverage in a secure deployment guide. The _IPv6 Specification_ is explained well by both guides (BSI = 0.75 _vs._ NIST = 1.0), but is discussed in much more detail by the NIST guide (BSI = 0.4 _vs._ NIST = 0.75). In respect to the importance ranking of 6.17 the results are still good for both guides. The other two subcategories are relatively close together in terms of completeness as well as depth. Figure 9 shows the average depth in this category. Both guides provide on average medium depth for the RFCs they cover (around 0.6). _IPv6 Specification_ is explained in much more detail by the NIST guide. _Address Features_ are important for both guides. The BSI guide on average is even more detailed in describing the RFCs it covers than the NIST guide. The figure also shows that the BSI guide does not deal with the subcategories _Header_ and _Mobile IPv6_, while the NIST guide at least has almost medium coverage for _Mobile IPv6_. The difference between the BSI and NIST guides is surprisingly large in the category _IPsec and ICMPv6_. While the NIST guide covers 86% of all relevant RFCs, the BSI guide merely covers 20%. This also shows in the depth score, with a difference of 0.29 points in depth in favor of the NIST guide. There are two subcategories that have a huge impact on the outcome of the results for the main category. Those two are _IKEv2_ and _Cryptographic Methods_. On the BSI side, both subcategories were completely ignored.